diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/README.md b/lib/node_modules/@stdlib/stats/strided/snanstdev/README.md new file mode 100644 index 000000000000..419d172cc560 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/README.md @@ -0,0 +1,419 @@ + + +# snanstdev + +> Calculate the [standard deviation][standard-deviation] of a single-precision floating-point strided array, ignoring `NaN` values. + +
+ +The population [standard deviation][standard-deviation] of a finite size population of size `N` is given by + + + +```math +\sigma = \sqrt{\frac{1}{N} \sum_{i=0}^{N-1} (x_i - \mu)^2} +``` + + + + + +where the population mean is given by + + + +```math +\mu = \frac{1}{N} \sum_{i=0}^{N-1} x_i +``` + + + + + +Often in the analysis of data, the true population [standard deviation][standard-deviation] is not known _a priori_ and must be estimated from a sample drawn from the population distribution. If one attempts to use the formula for the population [standard deviation][standard-deviation], the result is biased and yields an **uncorrected sample standard deviation**. To compute a **corrected sample standard deviation** for a sample of size `n`, + + + +```math +s = \sqrt{\frac{1}{n-1} \sum_{i=0}^{n-1} (x_i - \bar{x})^2} +``` + + + + + +where the sample mean is given by + + + +```math +\bar{x} = \frac{1}{n} \sum_{i=0}^{n-1} x_i +``` + + + + + +The use of the term `n-1` is commonly referred to as Bessel's correction. Note, however, that applying Bessel's correction can increase the mean squared error between the sample standard deviation and population standard deviation. Depending on the characteristics of the population distribution, other correction factors (e.g., `n-1.5`, `n+1`, etc) can yield better estimators. + +
+ + + +
+ +## Usage + +```javascript +var snanstdev = require( '@stdlib/stats/strided/snanstdev' ); +``` + +#### snanstdev( N, correction, x, strideX ) + +Computes the [standard deviation][standard-deviation] of a single-precision floating-point strided array, ignoring `NaN` values. + +```javascript +var Float32Array = require( '@stdlib/array/float32' ); + +var x = new Float32Array([ + 1.0, 2.0, 2.0, -7.0, -2.0, 3.0, 4.0, 2.0, NaN, NaN +]); + +var v = snanstdev( 5, 1, x, 2 ); +// returns 2.5 +``` + +The function has the following parameters: + +- **N**: number of indexed elements. +- **correction**: degrees of freedom adjustment. Setting this parameter to a value other than `0` has the effect of adjusting the divisor during the calculation of the [standard deviation][standard-deviation] according to `n-c` where `c` corresponds to the provided degrees of freedom adjustment and `n` corresponds to the number of non-`NaN` indexed elements. When computing the [standard deviation][standard-deviation] of a population, setting this parameter to `0` is the standard choice (i.e., the provided array contains data constituting an entire population). When computing the corrected sample [standard deviation][standard-deviation], setting this parameter to `1` is the standard choice (i.e., the provided array contains data sampled from a larger population; this is commonly referred to as Bessel's correction). +- **x**: input [`Float32Array`][@stdlib/array/float32]. +- **strideX**: stride length for `x`. + +The `N` and stride parameters determine which elements in the strided array are accessed at runtime. For example, to compute the [standard deviation][standard-deviation] of every other element in `x`, + +```javascript +var Float32Array = require( '@stdlib/array/float32' ); + +var x = new Float32Array([ + 1.0, 2.0, 2.0, -7.0, -2.0, 3.0, 4.0, 2.0, NaN, NaN +]); + +var v = snanstdev( 5, 1, x, 2 ); +// returns 2.5 +``` + +Note that indexing is relative to the first index. To introduce an offset, use [`typed array`][mdn-typed-array] views. + + + +```javascript +var Float32Array = require( '@stdlib/array/float32' ); + +var x0 = new Float32Array([ + 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN +]); +var x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); + +var v = snanstdev( 4, 1, x1, 2 ); +// returns 2.5 +``` + +#### snanstdev.ndarray( N, correction, x, strideX, offsetX ) + +Computes the [standard deviation][standard-deviation] of a single-precision floating-point strided array, ignoring `NaN` values and using alternative indexing semantics. + +```javascript +var Float32Array = require( '@stdlib/array/float32' ); + +var x = new Float32Array( [ 1.0, -2.0, NaN, 2.0 ] ); + +var v = snanstdev.ndarray( x.length, 1, x, 1, 0 ); +// returns ~2.0817 +``` + +The function has the following additional parameters: + +- **offsetX**: starting index for `x`. + +While [`typed array`][mdn-typed-array] views mandate a view offset based on the underlying buffer, the offset parameter supports indexing semantics based on a starting index. For example, to calculate the [standard deviation][standard-deviation] for every other element in `x` starting from the second element + +```javascript +var Float32Array = require( '@stdlib/array/float32' ); + +var x = new Float32Array([ + 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN +]); + +var v = snanstdev.ndarray( 4, 1, x, 2, 1 ); +// returns 2.5 +``` + +
+ + + +
+ +## Notes + +- If `N <= 0`, both functions return `NaN`. +- If `n - c` is less than or equal to `0` (where `c` corresponds to the provided degrees of freedom adjustment and `n` corresponds to the number of non-`NaN` indexed elements), both functions return `NaN`. +- Depending on the environment, the typed versions ([`dnanstdev`][@stdlib/stats/base/dnanstdev], [`snanstdev`][@stdlib/stats/base/snanstdev], etc.) are likely to be significantly more performant. + +
+ + + +
+ +## Examples + + + +```javascript +var discreteUniform = require( '@stdlib/random/array/discrete-uniform' ); +var bernoulli = require( '@stdlib/random/array/bernoulli' ); +var Float32Array = require( '@stdlib/array/float32' ); +var snanstdev = require( '@stdlib/stats/strided/snanstdev' ); + +var x = discreteUniform( 10, -50, 50, { + 'dtype': 'float32' +}); +console.log( x ); + +// Create a boolean mask: +var mask = bernoulli( x.length, 0.2, { + 'dtype': 'generic' +}); +console.log( mask ); + +// Randomly set values to NaN: +var i; +for ( i = 0; i < x.length; i++ ) { + if ( mask[ i ] ) { + x[ i ] = NaN; + } +} +console.log( x ); + +var v = snanstdev( x.length, 1, x, 1 ); +console.log( v ); +``` + +
+ + + + + +* * * + +
+ +## C APIs + + + +
+ +
+ + + + + +
+ +### Usage + +```c +#include "stdlib/stats/strided/snanstdev.h" +``` + +#### stdlib_strided_snanstdev( N, correction, \*X, strideX ) + +Computes the [standard deviation][standard-deviation] of a single-precision floating-point strided array, ignoring `NaN` values. + +```c +const float x[] = { 1.0f, 2.0f, 0.0f/0.0f, 4.0f }; + +float v = stdlib_strided_snanstdev( 4, 1.0f, x, 1 ); +// returns ~1.5275 +``` + +The function accepts the following arguments: + +- **N**: `[in] CBLAS_INT` number of indexed elements. +- **correction**: `[in] float` degrees of freedom adjustment. Setting this parameter to a value other than `0` has the effect of adjusting the divisor during the calculation of the [standard deviation][standard-deviation] according to `n-c` where `c` corresponds to the provided degrees of freedom adjustment and `n` corresponds to the number of non-`NaN` indexed elements. When computing the [standard deviation][standard-deviation] of a population, setting this parameter to `0` is the standard choice (i.e., the provided array contains data constituting an entire population). When computing the corrected sample [standard deviation][standard-deviation], setting this parameter to `1` is the standard choice (i.e., the provided array contains data sampled from a larger population; this is commonly referred to as Bessel's correction). +- **X**: `[in] float*` input array. +- **strideX**: `[in] CBLAS_INT` stride length for `X`. + +```c +float stdlib_strided_snanstdev( const CBLAS_INT N, const float correction, const float *X, const CBLAS_INT strideX ); +``` + +#### stdlib_strided_snanstdev_ndarray( N, correction, \*X, strideX, offsetX ) + +Computes the [standard deviation][standard-deviation] of a single-precision floating-point strided array, ignoring `NaN` values and using alternative indexing semantics. + +```c +const float x[] = { 1.0f, 2.0f, 0.0f/0.0f, 4.0f }; + +float v = stdlib_strided_snanstdev_ndarray( 4, 1.0f, x, 1, 0 ); +// returns ~1.5275 +``` + +The function accepts the following arguments: + +- **N**: `[in] CBLAS_INT` number of indexed elements. +- **correction**: `[in] float` degrees of freedom adjustment. Setting this parameter to a value other than `0` has the effect of adjusting the divisor during the calculation of the [standard deviation][standard-deviation] according to `n-c` where `c` corresponds to the provided degrees of freedom adjustment and `n` corresponds to the number of non-`NaN` indexed elements. When computing the [standard deviation][standard-deviation] of a population, setting this parameter to `0` is the standard choice (i.e., the provided array contains data constituting an entire population). When computing the corrected sample [standard deviation][standard-deviation], setting this parameter to `1` is the standard choice (i.e., the provided array contains data sampled from a larger population; this is commonly referred to as Bessel's correction). +- **X**: `[in] float*` input array. +- **strideX**: `[in] CBLAS_INT` stride length for `X`. +- **offsetX**: `[in] CBLAS_INT` starting index for `X`. + +```c +float stdlib_strided_snanstdev_ndarray( const CBLAS_INT N, const float correction, const float *X, const CBLAS_INT strideX, const CBLAS_INT offsetX ); +``` + +
+ + + + + +
+ +
+ + + + + +
+ +### Examples + +```c +#include "stdlib/stats/strided/snanstdev.h" +#include + +int main( void ) { + // Create a strided array: + const float x[] = { 1.0f, 2.0f, 3.0f, 4.0f, 0.0f/0.0f, 6.0f, 7.0f, 8.0f }; + + // Specify the number of elements: + const int N = 8; + + // Specify the stride length: + const int strideX = 1; + + // Compute the standard deviation: + float v = stdlib_strided_snanstdev( N, 1.0f, x, strideX ); + + // Print the result: + printf( "sample standard deviation: %f\n", v ); +} +``` + +
+ + + +
+ + + +
+ +* * * + +## References + +- Neely, Peter M. 1966. "Comparison of Several Algorithms for Computation of Means, Standard Deviations and Correlation Coefficients." _Communications of the ACM_ 9 (7). Association for Computing Machinery: 496–99. doi:[10.1145/365719.365958][@neely:1966a]. +- Schubert, Erich, and Michael Gertz. 2018. "Numerically Stable Parallel Computation of (Co-)Variance." In _Proceedings of the 30th International Conference on Scientific and Statistical Database Management_. New York, NY, USA: Association for Computing Machinery. doi:[10.1145/3221269.3223036][@schubert:2018a]. + +
+ + + + + +
+ +* * * + +## See Also + +- [`@stdlib/stats/strided/dnanstdev`][@stdlib/stats/strided/dnanstdev]: calculate the standard deviation of a double-precision floating-point strided array ignoring NaN values. +- [`@stdlib/stats/strided/sstdev`][@stdlib/stats/strided/sstdev]: calculate the standard deviation of a single-precision floating-point strided array. +- [`@stdlib/stats/strided/snanvariance`][@stdlib/stats/strided/snanvariance]: calculate the variance of a single-precision floating-point strided array ignoring NaN values. +- [`@stdlib/stats/strided/nanstdev`][@stdlib/stats/strided/nanstdev]: calculate the standard deviation of a strided array ignoring NaN values. + +
+ + + + + +
+ +[standard-deviation]: https://en.wikipedia.org/wiki/Standard_deviation + +[@stdlib/array/float32]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/array/float32 + +[mdn-typed-array]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray + +[@neely:1966a]: https://doi.org/10.1145/365719.365958 + +[@schubert:2018a]: https://doi.org/10.1145/3221269.3223036 + + + +[@stdlib/stats/strided/dnanstdev]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/strided/dnanstdev + +[@stdlib/stats/strided/sstdev]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/strided/sstdev + +[@stdlib/stats/strided/snanvariance]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/strided/snanvariance + +[@stdlib/stats/strided/nanstdev]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/strided/nanstdev + +[@stdlib/stats/base/dnanstdev]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/base/dnanstdev + +[@stdlib/stats/base/snanstdev]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/base/snanstdev + + + +
+ + diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.js b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.js new file mode 100644 index 000000000000..649c9113b82e --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.js @@ -0,0 +1,106 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +'use strict'; + +// MODULES // + +var bench = require( '@stdlib/bench' ); +var uniform = require( '@stdlib/random/array/uniform' ); +var isnan = require( '@stdlib/math/base/assert/is-nan' ); +var format = require( '@stdlib/string/format' ); +var pkg = require( './../package.json' ).name; +var snanstdev = require( './../lib/main.js' ); + + +// MAIN // + +bench( pkg, function benchmark( b ) { + var x; + var v; + var i; + + x = uniform( 10, -10.0, 10.0, { + 'dtype': 'float32' + }); + + b.tic(); + for ( i = 0; i < b.iterations; i++ ) { + x[ 0 ] = i; + v = snanstdev( x.length, 1, x, 1 ); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + } + b.toc(); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + b.pass( 'benchmark finished' ); + b.end(); +}); + +bench( format( '%s::population', pkg ), function benchmark( b ) { + var x; + var v; + var i; + + x = uniform( 10, -10.0, 10.0, { + 'dtype': 'float32' + }); + + b.tic(); + for ( i = 0; i < b.iterations; i++ ) { + x[ 0 ] = i; + v = snanstdev( x.length, 0, x, 1 ); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + } + b.toc(); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + b.pass( 'benchmark finished' ); + b.end(); +}); + +bench( format( '%s::sample', pkg ), function benchmark( b ) { + var x; + var v; + var i; + + x = uniform( 10, -10.0, 10.0, { + 'dtype': 'float32' + }); + + b.tic(); + for ( i = 0; i < b.iterations; i++ ) { + x[ 0 ] = i; + v = snanstdev( x.length, 1, x, 1 ); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + } + b.toc(); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + b.pass( 'benchmark finished' ); + b.end(); +}); diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.native.js b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.native.js new file mode 100644 index 000000000000..7871e2152aaf --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.native.js @@ -0,0 +1,65 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +'use strict'; + +// MODULES // + +var resolve = require( 'path' ).resolve; +var bench = require( '@stdlib/bench' ); +var uniform = require( '@stdlib/random/array/uniform' ); +var isnan = require( '@stdlib/math/base/assert/is-nan' ); +var format = require( '@stdlib/string/format' ); +var tryRequire = require( '@stdlib/utils/try-require' ); +var pkg = require( './../package.json' ).name; + + +// VARIABLES // + +var snanstdev = tryRequire( resolve( __dirname, './../lib/snanstdev.native.js' ) ); +var opts = { + 'skip': ( snanstdev instanceof Error ) +}; + + +// MAIN // + +bench( format( '%s::native', pkg ), opts, function benchmark( b ) { + var x; + var v; + var i; + + x = uniform( 10, -10.0, 10.0, { + 'dtype': 'float32' + }); + + b.tic(); + for ( i = 0; i < b.iterations; i++ ) { + x[ 0 ] = i; + v = snanstdev( x.length, 1, x, 1 ); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + } + b.toc(); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + b.pass( 'benchmark finished' ); + b.end(); +}); diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.ndarray.js b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.ndarray.js new file mode 100644 index 000000000000..aaa766b36b86 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.ndarray.js @@ -0,0 +1,56 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +'use strict'; + +// MODULES // + +var bench = require( '@stdlib/bench' ); +var uniform = require( '@stdlib/random/array/uniform' ); +var isnan = require( '@stdlib/math/base/assert/is-nan' ); +var format = require( '@stdlib/string/format' ); +var pkg = require( './../package.json' ).name; +var snanstdev = require( './../lib/ndarray.js' ); + + +// MAIN // + +bench( format( '%s::ndarray', pkg ), function benchmark( b ) { + var x; + var v; + var i; + + x = uniform( 10, -10.0, 10.0, { + 'dtype': 'float32' + }); + + b.tic(); + for ( i = 0; i < b.iterations; i++ ) { + x[ 0 ] = i; + v = snanstdev( x.length, 1, x, 1, 0 ); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + } + b.toc(); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + b.pass( 'benchmark finished' ); + b.end(); +}); diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.ndarray.native.js b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.ndarray.native.js new file mode 100644 index 000000000000..9894611e4617 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/benchmark.ndarray.native.js @@ -0,0 +1,65 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +'use strict'; + +// MODULES // + +var resolve = require( 'path' ).resolve; +var bench = require( '@stdlib/bench' ); +var uniform = require( '@stdlib/random/array/uniform' ); +var isnan = require( '@stdlib/math/base/assert/is-nan' ); +var format = require( '@stdlib/string/format' ); +var tryRequire = require( '@stdlib/utils/try-require' ); +var pkg = require( './../package.json' ).name; + + +// VARIABLES // + +var snanstdev = tryRequire( resolve( __dirname, './../lib/ndarray.native.js' ) ); +var opts = { + 'skip': ( snanstdev instanceof Error ) +}; + + +// MAIN // + +bench( format( '%s::ndarray:native', pkg ), opts, function benchmark( b ) { + var x; + var v; + var i; + + x = uniform( 10, -10.0, 10.0, { + 'dtype': 'float32' + }); + + b.tic(); + for ( i = 0; i < b.iterations; i++ ) { + x[ 0 ] = i; + v = snanstdev( x.length, 1, x, 1, 0 ); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + } + b.toc(); + if ( isnan( v ) ) { + b.fail( 'should not return NaN' ); + } + b.pass( 'benchmark finished' ); + b.end(); +}); diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/c/Makefile b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/c/Makefile new file mode 100644 index 000000000000..0756dc7da20a --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/c/Makefile @@ -0,0 +1,146 @@ +#/ +# @license Apache-2.0 +# +# Copyright (c) 2026 The Stdlib Authors. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +#/ + +# VARIABLES # + +ifndef VERBOSE + QUIET := @ +else + QUIET := +endif + +# Determine the OS ([1][1], [2][2]). +# +# [1]: https://en.wikipedia.org/wiki/Uname#Examples +# [2]: http://stackoverflow.com/a/27776822/2225624 +OS ?= $(shell uname) +ifneq (, $(findstring MINGW,$(OS))) + OS := WINNT +else +ifneq (, $(findstring MSYS,$(OS))) + OS := WINNT +else +ifneq (, $(findstring CYGWIN,$(OS))) + OS := WINNT +else +ifneq (, $(findstring Windows_NT,$(OS))) + OS := WINNT +endif +endif +endif +endif + +# Define the program used for compiling C source files: +ifdef C_COMPILER + CC := $(C_COMPILER) +else + CC := gcc +endif + +# Define the command-line options when compiling C files: +CFLAGS ?= \ + -std=c99 \ + -O3 \ + -Wall \ + -pedantic + +# Determine whether to generate position independent code ([1][1], [2][2]). +# +# [1]: https://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options.html#Code-Gen-Options +# [2]: http://stackoverflow.com/questions/5311515/gcc-fpic-option +ifeq ($(OS), WINNT) + fPIC ?= +else + fPIC ?= -fPIC +endif + +# List of includes (e.g., `-I /foo/bar -I /beep/boop/include`): +INCLUDE ?= + +# List of source files: +SOURCE_FILES ?= + +# List of libraries (e.g., `-lopenblas -lpthread`): +LIBRARIES ?= + +# List of library paths (e.g., `-L /foo/bar -L /beep/boop`): +LIBPATH ?= + +# List of C targets: +c_targets := benchmark.length.out + + +# RULES # + +#/ +# Compiles source files. +# +# @param {string} [C_COMPILER] - C compiler (e.g., `gcc`) +# @param {string} [CFLAGS] - C compiler options +# @param {(string|void)} [fPIC] - compiler flag determining whether to generate position independent code (e.g., `-fPIC`) +# @param {string} [INCLUDE] - list of includes (e.g., `-I /foo/bar -I /beep/boop/include`) +# @param {string} [SOURCE_FILES] - list of source files +# @param {string} [LIBPATH] - list of library paths (e.g., `-L /foo/bar -L /beep/boop`) +# @param {string} [LIBRARIES] - list of libraries (e.g., `-lopenblas -lpthread`) +# +# @example +# make +# +# @example +# make all +#/ +all: $(c_targets) + +.PHONY: all + +#/ +# Compiles C source files. +# +# @private +# @param {string} CC - C compiler (e.g., `gcc`) +# @param {string} CFLAGS - C compiler options +# @param {(string|void)} fPIC - compiler flag determining whether to generate position independent code (e.g., `-fPIC`) +# @param {string} INCLUDE - list of includes (e.g., `-I /foo/bar`) +# @param {string} SOURCE_FILES - list of source files +# @param {string} LIBPATH - list of library paths (e.g., `-L /foo/bar`) +# @param {string} LIBRARIES - list of libraries (e.g., `-lopenblas`) +#/ +$(c_targets): %.out: %.c + $(QUIET) $(CC) $(CFLAGS) $(fPIC) $(INCLUDE) -o $@ $(SOURCE_FILES) $< $(LIBPATH) -lm $(LIBRARIES) + +#/ +# Runs compiled benchmarks. +# +# @example +# make run +#/ +run: $(c_targets) + $(QUIET) ./$< + +.PHONY: run + +#/ +# Removes generated files. +# +# @example +# make clean +#/ +clean: + $(QUIET) -rm -f *.o *.out + +.PHONY: clean diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/c/benchmark.length.c b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/c/benchmark.length.c new file mode 100644 index 000000000000..f99c77514fff --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/benchmark/c/benchmark.length.c @@ -0,0 +1,157 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +#include "stdlib/stats/strided/snanstdev.h" +#include +#include +#include +#include +#include + +#define NAME "snanstdev" +#define ITERATIONS 1000000 +#define REPEATS 3 + +/** +* Prints the TAP version. +*/ +static void print_version( void ) { + printf( "TAP version 13\n" ); +} + +/** +* Prints the TAP summary. +* +* @param total total number of tests +* @param passing total number of passing tests +*/ +static void print_summary( int total, int passing ) { + printf( "#\n" ); + printf( "1..%d\n", total ); // TAP plan + printf( "# total %d\n", total ); + printf( "# pass %d\n", passing ); + printf( "#\n" ); + printf( "# ok\n" ); +} + +/** +* Prints benchmarks results. +* +* @param elapsed elapsed time in seconds +*/ +static void print_results( double elapsed ) { + double rate = (double)ITERATIONS / elapsed; + printf( " ---\n" ); + printf( " iterations: %d\n", ITERATIONS ); + printf( " elapsed: %0.9f\n", elapsed ); + printf( " rate: %0.9f\n", rate ); + printf( " ...\n" ); +} + +/** +* Returns a clock time. +* +* @return clock time +*/ +static double tic( void ) { + struct timeval now; + gettimeofday( &now, NULL ); + return (double)now.tv_sec + (double)now.tv_usec/1.0e6; +} + +/** +* Generates a random number on the interval [0,1]. +* +* @return random number +*/ +static float rand_float( void ) { + int r = rand(); + return (float)r / ( (float)RAND_MAX + 1.0f ); +} + +/** +* Runs a benchmark. +* +* @param len array length +* @return elapsed time in seconds +*/ +static double benchmark( int len ) { + double elapsed; + float x[ len ]; + double t; + float v; + int i; + + for ( i = 0; i < len; i++ ) { + if ( rand_float() < 0.2 ) { + x[ i ] = 0.0f / 0.0f; // NaN + } else { + x[ i ] = ( rand_float() * 200.0f ) - 100.0f; + } + } + t = tic(); + for ( i = 0; i < ITERATIONS; i++ ) { + v = stdlib_strided_snanstdev( len, 1.0f, x, 1 ); + if ( v != v ) { + printf( "unexpected result\n" ); + break; + } + } + elapsed = tic() - t; + if ( v != v ) { + printf( "unexpected result\n" ); + } + return elapsed; +} + +/** +* Main execution sequence. +*/ +int main( void ) { + double elapsed; + int count; + int len; + int min; + int max; + int f; + int i; + int j; + + // Use the current time to seed the random number generator: + srand( time( NULL ) ); + + print_version(); + count = 0; + + // Benchmark various array lengths: + min = 1; + max = 6; + for ( i = min; i <= max; i++ ) { + len = pow( 10, i ); + elapsed = 0.0; + for ( j = 0; j < REPEATS; j++ ) { + count += 1; + printf( "# c::%s:len=%d\n", NAME, len ); + elapsed += benchmark( len ); + printf( "ok %d benchmark finished\n", count ); + } + elapsed /= (double)REPEATS; + print_results( elapsed ); + } + print_summary( count, count ); +} diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/binding.gyp b/lib/node_modules/@stdlib/stats/strided/snanstdev/binding.gyp new file mode 100644 index 000000000000..0d6508a12e99 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/binding.gyp @@ -0,0 +1,170 @@ +# @license Apache-2.0 +# +# Copyright (c) 2026 The Stdlib Authors. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +# A `.gyp` file for building a Node.js native add-on. +# +# [1]: https://gyp.gsrc.io/docs/InputFormatReference.md +# [2]: https://gyp.gsrc.io/docs/UserDocumentation.md +{ + # List of files to include in this file: + 'includes': [ + './include.gypi', + ], + + # Define variables to be used throughout the configuration for all targets: + 'variables': { + # Target name should match the add-on export name: + 'addon_target_name%': 'addon', + + # Set variables based on the host OS: + 'conditions': [ + [ + 'OS=="win"', + { + # Define the object file suffix: + 'obj': 'obj', + }, + { + # Define the object file suffix: + 'obj': 'o', + } + ], # end condition (OS=="win") + ], # end conditions + }, # end variables + + # Define compile targets: + 'targets': [ + + # Target to generate an add-on: + { + # The target name should match the add-on export name: + 'target_name': '<(addon_target_name)', + + # Define dependencies: + 'dependencies': [], + + # Define directories which contain relevant include headers: + 'include_dirs': [ + # Local include directory: + '<@(include_dirs)', + ], + + # List of source files: + 'sources': [ + '<@(src_files)', + ], + + # Settings which should be applied when a target's object files are used as linker input: + 'link_settings': { + # Define libraries: + 'libraries': [ + '<@(libraries)', + ], + + # Define library directories: + 'library_dirs': [ + '<@(library_dirs)', + ], + }, + + # C/C++ compiler flags: + 'cflags': [ + # Enable commonly used warning options: + '-Wall', + + # Aggressive optimization: + '-O3', + ], + + # C specific compiler flags: + 'cflags_c': [ + # Specify the C standard to which a program is expected to conform: + '-std=c99', + ], + + # C++ specific compiler flags: + 'cflags_cpp': [ + # Specify the C++ standard to which a program is expected to conform: + '-std=c++11', + ], + + # Linker flags: + 'ldflags': [], + + # Apply conditions based on the host OS: + 'conditions': [ + [ + 'OS=="mac"', + { + # Linker flags: + 'ldflags': [ + '-undefined dynamic_lookup', + '-Wl,-no-pie', + '-Wl,-search_paths_first', + ], + }, + ], # end condition (OS=="mac") + [ + 'OS!="win"', + { + # C/C++ flags: + 'cflags': [ + # Generate platform-independent code: + '-fPIC', + ], + }, + ], # end condition (OS!="win") + ], # end conditions + }, # end target <(addon_target_name) + + # Target to copy a generated add-on to a standard location: + { + 'target_name': 'copy_addon', + + # Declare that the output of this target is not linked: + 'type': 'none', + + # Define dependencies: + 'dependencies': [ + # Require that the add-on be generated before building this target: + '<(addon_target_name)', + ], + + # Define a list of actions: + 'actions': [ + { + 'action_name': 'copy_addon', + 'message': 'Copying addon...', + + # Explicitly list the inputs in the command-line invocation below: + 'inputs': [], + + # Declare the expected outputs: + 'outputs': [ + '<(addon_output_dir)/<(addon_target_name).node', + ], + + # Define the command-line invocation: + 'action': [ + 'cp', + '<(PRODUCT_DIR)/<(addon_target_name).node', + '<(addon_output_dir)/<(addon_target_name).node', + ], + }, + ], # end actions + }, # end target copy_addon + ], # end targets +} diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_corrected_sample_standard_deviation.svg b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_corrected_sample_standard_deviation.svg new file mode 100644 index 000000000000..6af85c9d5732 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_corrected_sample_standard_deviation.svg @@ -0,0 +1,73 @@ + +s equals StartRoot StartFraction 1 Over n minus 1 EndFraction sigma-summation Underscript i equals 0 Overscript n minus 1 Endscripts left-parenthesis x Subscript i Baseline minus x overbar right-parenthesis squared EndRoot + + + \ No newline at end of file diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_population_mean.svg b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_population_mean.svg new file mode 100644 index 000000000000..4bbdf0d2a56f --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_population_mean.svg @@ -0,0 +1,42 @@ + +mu equals StartFraction 1 Over upper N EndFraction sigma-summation Underscript i equals 0 Overscript upper N minus 1 Endscripts x Subscript i + + + \ No newline at end of file diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_population_standard_deviation.svg b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_population_standard_deviation.svg new file mode 100644 index 000000000000..ad431efeff2a --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_population_standard_deviation.svg @@ -0,0 +1,66 @@ + +sigma equals StartRoot StartFraction 1 Over upper N EndFraction sigma-summation Underscript i equals 0 Overscript upper N minus 1 Endscripts left-parenthesis x Subscript i Baseline minus mu right-parenthesis squared EndRoot + + + \ No newline at end of file diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_sample_mean.svg b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_sample_mean.svg new file mode 100644 index 000000000000..aea7a5f6687a --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/img/equation_sample_mean.svg @@ -0,0 +1,43 @@ + +x overbar equals StartFraction 1 Over n EndFraction sigma-summation Underscript i equals 0 Overscript n minus 1 Endscripts x Subscript i + + + \ No newline at end of file diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/repl.txt b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/repl.txt new file mode 100644 index 000000000000..7788585242e1 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/repl.txt @@ -0,0 +1,120 @@ + +{{alias}}( N, correction, x, strideX ) + Computes the standard deviation of a single-precision floating-point + strided array ignoring NaN values. + + The `N` and stride parameters determine which elements are accessed at + runtime. + + Indexing is relative to the first index. To introduce an offset, use a + typed array view. + + If `N <= 0`, the function returns `NaN`. + + If `n - c` is less than or equal to `0` (where `c` corresponds to the + provided degrees of freedom adjustment and `n` corresponds to the number of + non-NaN indexed elements), the function returns `NaN`. + + Parameters + ---------- + N: integer + Number of indexed elements. + + correction: number + Degrees of freedom adjustment. Setting this parameter to a value other + than `0` has the effect of adjusting the divisor during the calculation + of the standard deviation according to `n-c` where `c` corresponds to + the provided degrees of freedom adjustment and `n` corresponds to the + number of non-NaN indexed elements. When computing the standard + deviation of a population, setting this parameter to `0` is the + standard choice (i.e., the provided array contains data constituting an + entire population). When computing the corrected sample standard + deviation, setting this parameter to `1` is the standard choice (i.e., + the provided array contains data sampled from a larger population; this + is commonly referred to as Bessel's correction). + + x: Float32Array + Input array. + + strideX: integer + Index increment. + + Returns + ------- + out: number + Standard deviation. + + Examples + -------- + // Standard Usage: + > var x = new {{alias:@stdlib/array/float32}}( [ 1.0, -2.0, NaN, 2.0 ] ); + > {{alias}}( x.length, 1, x, 1 ) + ~2.0817 + + // Using `N` and stride parameters: + > x = new {{alias:@stdlib/array/float32}}( [ -2.0, 1.0, 1.0, -5.0, 2.0, -1.0, NaN, NaN ] ); + > {{alias}}( 4, 1, x, 2 ) + ~2.0817 + + // Using view offsets: + > var x0 = new {{alias:@stdlib/array/float32}}( [ 1.0, -2.0, 3.0, 2.0, 5.0, -1.0, NaN, NaN ] ); + > var x1 = new {{alias:@stdlib/array/float32}}( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); + > {{alias}}( 4, 1, x1, 2 ) + ~2.0817 + + +{{alias}}.ndarray( N, correction, x, strideX, offsetX ) + Computes the standard deviation of a single-precision floating-point + strided array ignoring NaN values and using alternative indexing semantics. + + While typed array views mandate a view offset based on the underlying + buffer, the offset parameter supports indexing semantics based on a + starting index. + + Parameters + ---------- + N: integer + Number of indexed elements. + + correction: number + Degrees of freedom adjustment. Setting this parameter to a value other + than `0` has the effect of adjusting the divisor during the calculation + of the standard deviation according to `n-c` where `c` corresponds to + the provided degrees of freedom adjustment and `n` corresponds to the + number of non-NaN indexed elements. When computing the standard + deviation of a population, setting this parameter to `0` is the + standard choice (i.e., the provided array contains data constituting an + entire population). When computing the corrected sample standard + deviation, setting this parameter to `1` is the standard choice (i.e., + the provided array contains data sampled from a larger population; this + is commonly referred to as Bessel's correction). + + x: Float32Array + Input array. + + strideX: integer + Index increment. + + offsetX: integer + Starting index. + + Returns + ------- + out: number + Standard deviation. + + Examples + -------- + // Standard Usage: + > var x = new {{alias:@stdlib/array/float32}}( [ 1.0, -2.0, NaN, 2.0 ] ); + > {{alias}}.ndarray( x.length, 1, x, 1, 0 ) + ~2.0817 + + // Using offset parameter: + > var x = new {{alias:@stdlib/array/float32}}( [ 1.0, -2.0, 3.0, 2.0, 5.0, -1.0, NaN, NaN ] ); + > {{alias}}.ndarray( 4, 1, x, 2, 1 ) + ~2.0817 + + See Also + -------- + diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/types/index.d.ts b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/types/index.d.ts new file mode 100644 index 000000000000..b9a92fe63ffc --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/types/index.d.ts @@ -0,0 +1,95 @@ +/* +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +// TypeScript Version: 4.1 + +/** +* Interface describing `snanstdev`. +*/ +interface Routine { + /** + * Computes the standard deviation of a single-precision floating-point strided array, ignoring NaN values. + * + * @param N - number of indexed elements + * @param correction - degrees of freedom adjustment + * @param x - input array + * @param strideX - stride length + * @returns standard deviation + * + * @example + * var Float32Array = require( '@stdlib/array/float32' ); + * + * var x = new Float32Array( [ 1.0, -2.0, NaN, 2.0 ] ); + * + * var v = snanstdev( x.length, 1, x, 1 ); + * // returns ~2.0817 + */ + ( N: number, correction: number, x: Float32Array, strideX: number ): number; + + /** + * Computes the standard deviation of a single-precision floating-point strided array, ignoring NaN values and using alternative indexing semantics. + * + * @param N - number of indexed elements + * @param correction - degrees of freedom adjustment + * @param x - input array + * @param strideX - stride length + * @param offsetX - starting index + * @returns standard deviation + * + * @example + * var Float32Array = require( '@stdlib/array/float32' ); + * + * var x = new Float32Array( [ 1.0, -2.0, NaN, 2.0 ] ); + * + * var v = snanstdev.ndarray( x.length, 1, x, 1, 0 ); + * // returns ~2.0817 + */ + ndarray( N: number, correction: number, x: Float32Array, strideX: number, offsetX: number ): number; +} + +/** +* Computes the standard deviation of a single-precision floating-point strided array, ignoring NaN values. +* +* @param N - number of indexed elements +* @param correction - degrees of freedom adjustment +* @param x - input array +* @param strideX - stride length +* @returns standard deviation +* +* @example +* var Float32Array = require( '@stdlib/array/float32' ); +* +* var x = new Float32Array( [ 1.0, -2.0, NaN, 2.0 ] ); +* +* var v = snanstdev( x.length, 1, x, 1 ); +* // returns ~2.0817 +* +* @example +* var Float32Array = require( '@stdlib/array/float32' ); +* +* var x = new Float32Array( [ 1.0, -2.0, NaN, 2.0 ] ); +* +* var v = snanstdev.ndarray( x.length, 1, x, 1, 0 ); +* // returns ~2.0817 +*/ +declare var snanstdev: Routine; + + +// EXPORTS // + +export = snanstdev; diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/types/test.ts b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/types/test.ts new file mode 100644 index 000000000000..306d17061555 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/docs/types/test.ts @@ -0,0 +1,187 @@ +/* +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +import snanstdev = require( './index' ); + + +// TESTS // + +// The function returns a number... +{ + const x = new Float32Array( 10 ); + + snanstdev( x.length, 1, x, 1 ); // $ExpectType number +} + +// The compiler throws an error if the function is provided a first argument which is not a number... +{ + const x = new Float32Array( 10 ); + + snanstdev( '10', 1, x, 1 ); // $ExpectError + snanstdev( true, 1, x, 1 ); // $ExpectError + snanstdev( false, 1, x, 1 ); // $ExpectError + snanstdev( null, 1, x, 1 ); // $ExpectError + snanstdev( undefined, 1, x, 1 ); // $ExpectError + snanstdev( [], 1, x, 1 ); // $ExpectError + snanstdev( {}, 1, x, 1 ); // $ExpectError + snanstdev( ( x: number ): number => x, 1, x, 1 ); // $ExpectError +} + +// The compiler throws an error if the function is provided a second argument which is not a number... +{ + const x = new Float32Array( 10 ); + + snanstdev( x.length, '10', x, 1 ); // $ExpectError + snanstdev( x.length, true, x, 1 ); // $ExpectError + snanstdev( x.length, false, x, 1 ); // $ExpectError + snanstdev( x.length, null, x, 1 ); // $ExpectError + snanstdev( x.length, undefined, x, 1 ); // $ExpectError + snanstdev( x.length, [], x, 1 ); // $ExpectError + snanstdev( x.length, {}, x, 1 ); // $ExpectError + snanstdev( x.length, ( x: number ): number => x, x, 1 ); // $ExpectError +} + +// The compiler throws an error if the function is provided a third argument which is not a Float32Array... +{ + const x = new Float32Array( 10 ); + + snanstdev( x.length, 1, 10, 1 ); // $ExpectError + snanstdev( x.length, 1, '10', 1 ); // $ExpectError + snanstdev( x.length, 1, true, 1 ); // $ExpectError + snanstdev( x.length, 1, false, 1 ); // $ExpectError + snanstdev( x.length, 1, null, 1 ); // $ExpectError + snanstdev( x.length, 1, undefined, 1 ); // $ExpectError + snanstdev( x.length, 1, [], 1 ); // $ExpectError + snanstdev( x.length, 1, {}, 1 ); // $ExpectError + snanstdev( x.length, 1, ( x: number ): number => x, 1 ); // $ExpectError +} + +// The compiler throws an error if the function is provided a fourth argument which is not a number... +{ + const x = new Float32Array( 10 ); + + snanstdev( x.length, 1, x, '10' ); // $ExpectError + snanstdev( x.length, 1, x, true ); // $ExpectError + snanstdev( x.length, 1, x, false ); // $ExpectError + snanstdev( x.length, 1, x, null ); // $ExpectError + snanstdev( x.length, 1, x, undefined ); // $ExpectError + snanstdev( x.length, 1, x, [] ); // $ExpectError + snanstdev( x.length, 1, x, {} ); // $ExpectError + snanstdev( x.length, 1, x, ( x: number ): number => x ); // $ExpectError +} + +// The compiler throws an error if the function is provided an unsupported number of arguments... +{ + const x = new Float32Array( 10 ); + + snanstdev(); // $ExpectError + snanstdev( x.length ); // $ExpectError + snanstdev( x.length, 1 ); // $ExpectError + snanstdev( x.length, 1, x ); // $ExpectError + snanstdev( x.length, 1, x, 1, 10 ); // $ExpectError +} + +// Attached to main export is an `ndarray` method which returns a number... +{ + const x = new Float32Array( 10 ); + + snanstdev.ndarray( x.length, 1, x, 1, 0 ); // $ExpectType number +} + +// The compiler throws an error if the `ndarray` method is provided a first argument which is not a number... +{ + const x = new Float32Array( 10 ); + + snanstdev.ndarray( '10', 1, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( true, 1, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( false, 1, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( null, 1, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( undefined, 1, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( [], 1, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( {}, 1, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( ( x: number ): number => x, 1, x, 1, 0 ); // $ExpectError +} + +// The compiler throws an error if the `ndarray` method is provided a second argument which is not a number... +{ + const x = new Float32Array( 10 ); + + snanstdev.ndarray( x.length, '10', x, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, true, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, false, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, null, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, undefined, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, [], x, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, {}, x, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, ( x: number ): number => x, x, 1, 0 ); // $ExpectError +} + +// The compiler throws an error if the `ndarray` method is provided a third argument which is not a Float32Array... +{ + const x = new Float32Array( 10 ); + + snanstdev.ndarray( x.length, 1, 10, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, '10', 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, true, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, false, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, null, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, undefined, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, [], 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, {}, 1, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, ( x: number ): number => x, 1, 0 ); // $ExpectError +} + +// The compiler throws an error if the `ndarray` method is provided a fourth argument which is not a number... +{ + const x = new Float32Array( 10 ); + + snanstdev.ndarray( x.length, 1, x, '10', 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, true, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, false, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, null, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, undefined, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, [], 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, {}, 0 ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, ( x: number ): number => x, 0 ); // $ExpectError +} + +// The compiler throws an error if the `ndarray` method is provided a fifth argument which is not a number... +{ + const x = new Float32Array( 10 ); + + snanstdev.ndarray( x.length, 1, x, 1, '10' ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, 1, true ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, 1, false ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, 1, null ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, 1, undefined ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, 1, [] ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, 1, {} ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, 1, ( x: number ): number => x ); // $ExpectError +} + +// The compiler throws an error if the `ndarray` method is provided an unsupported number of arguments... +{ + const x = new Float32Array( 10 ); + + snanstdev.ndarray(); // $ExpectError + snanstdev.ndarray( x.length ); // $ExpectError + snanstdev.ndarray( x.length, 1 ); // $ExpectError + snanstdev.ndarray( x.length, 1, x ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, 1 ); // $ExpectError + snanstdev.ndarray( x.length, 1, x, 1, 0, 10 ); // $ExpectError +} diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/examples/c/Makefile b/lib/node_modules/@stdlib/stats/strided/snanstdev/examples/c/Makefile new file mode 100644 index 000000000000..c8f8e9a1517b --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/examples/c/Makefile @@ -0,0 +1,146 @@ +#/ +# @license Apache-2.0 +# +# Copyright (c) 2026 The Stdlib Authors. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +#/ + +# VARIABLES # + +ifndef VERBOSE + QUIET := @ +else + QUIET := +endif + +# Determine the OS ([1][1], [2][2]). +# +# [1]: https://en.wikipedia.org/wiki/Uname#Examples +# [2]: http://stackoverflow.com/a/27776822/2225624 +OS ?= $(shell uname) +ifneq (, $(findstring MINGW,$(OS))) + OS := WINNT +else +ifneq (, $(findstring MSYS,$(OS))) + OS := WINNT +else +ifneq (, $(findstring CYGWIN,$(OS))) + OS := WINNT +else +ifneq (, $(findstring Windows_NT,$(OS))) + OS := WINNT +endif +endif +endif +endif + +# Define the program used for compiling C source files: +ifdef C_COMPILER + CC := $(C_COMPILER) +else + CC := gcc +endif + +# Define the command-line options when compiling C files: +CFLAGS ?= \ + -std=c99 \ + -O3 \ + -Wall \ + -pedantic + +# Determine whether to generate position independent code ([1][1], [2][2]). +# +# [1]: https://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options.html#Code-Gen-Options +# [2]: http://stackoverflow.com/questions/5311515/gcc-fpic-option +ifeq ($(OS), WINNT) + fPIC ?= +else + fPIC ?= -fPIC +endif + +# List of includes (e.g., `-I /foo/bar -I /beep/boop/include`): +INCLUDE ?= + +# List of source files: +SOURCE_FILES ?= + +# List of libraries (e.g., `-lopenblas -lpthread`): +LIBRARIES ?= + +# List of library paths (e.g., `-L /foo/bar -L /beep/boop`): +LIBPATH ?= + +# List of C targets: +c_targets := example.out + + +# RULES # + +#/ +# Compiles source files. +# +# @param {string} [C_COMPILER] - C compiler (e.g., `gcc`) +# @param {string} [CFLAGS] - C compiler options +# @param {(string|void)} [fPIC] - compiler flag determining whether to generate position independent code (e.g., `-fPIC`) +# @param {string} [INCLUDE] - list of includes (e.g., `-I /foo/bar -I /beep/boop/include`) +# @param {string} [SOURCE_FILES] - list of source files +# @param {string} [LIBPATH] - list of library paths (e.g., `-L /foo/bar -L /beep/boop`) +# @param {string} [LIBRARIES] - list of libraries (e.g., `-lopenblas -lpthread`) +# +# @example +# make +# +# @example +# make all +#/ +all: $(c_targets) + +.PHONY: all + +#/ +# Compiles C source files. +# +# @private +# @param {string} CC - C compiler (e.g., `gcc`) +# @param {string} CFLAGS - C compiler options +# @param {(string|void)} fPIC - compiler flag determining whether to generate position independent code (e.g., `-fPIC`) +# @param {string} INCLUDE - list of includes (e.g., `-I /foo/bar`) +# @param {string} SOURCE_FILES - list of source files +# @param {string} LIBPATH - list of library paths (e.g., `-L /foo/bar`) +# @param {string} LIBRARIES - list of libraries (e.g., `-lopenblas`) +#/ +$(c_targets): %.out: %.c + $(QUIET) $(CC) $(CFLAGS) $(fPIC) $(INCLUDE) -o $@ $(SOURCE_FILES) $< $(LIBPATH) -lm $(LIBRARIES) + +#/ +# Runs compiled examples. +# +# @example +# make run +#/ +run: $(c_targets) + $(QUIET) ./$< + +.PHONY: run + +#/ +# Removes generated files. +# +# @example +# make clean +#/ +clean: + $(QUIET) -rm -f *.o *.out + +.PHONY: clean diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/examples/c/example.c b/lib/node_modules/@stdlib/stats/strided/snanstdev/examples/c/example.c new file mode 100644 index 000000000000..f4bb8533f0ba --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/examples/c/example.c @@ -0,0 +1,37 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +#include "stdlib/stats/strided/snanstdev.h" +#include + +int main( void ) { + // Create a strided array: + const float x[] = { 1.0f, 2.0f, 3.0f, 4.0f, 0.0f/0.0f, 6.0f, 7.0f, 8.0f }; + + // Specify the number of elements: + const int N = 8; + + // Specify the stride length: + const int strideX = 1; + + // Compute the standard deviation: + float v = stdlib_strided_snanstdev( N, 1.0f, x, strideX ); + + // Print the result: + printf( "sample standard deviation: %f\n", v ); +} diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/examples/index.js b/lib/node_modules/@stdlib/stats/strided/snanstdev/examples/index.js new file mode 100644 index 000000000000..1bc0b8c41964 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/examples/index.js @@ -0,0 +1,46 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +'use strict'; + +var discreteUniform = require( '@stdlib/random/array/discrete-uniform' ); +var bernoulli = require( '@stdlib/random/array/bernoulli' ); +var snanstdev = require( './../lib' ); + +var x = discreteUniform( 10, -50, 50, { + 'dtype': 'float32' +}); +console.log( x ); + +// Create a boolean mask: +var mask = bernoulli( x.length, 0.2, { + 'dtype': 'generic' +}); +console.log( mask ); + +// Randomly set values to NaN: +var i; +for ( i = 0; i < x.length; i++ ) { + if ( mask[ i ] ) { + x[ i ] = NaN; + } +} +console.log( x ); + +var v = snanstdev( x.length, 1, x, 1 ); +console.log( v ); diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/include.gypi b/lib/node_modules/@stdlib/stats/strided/snanstdev/include.gypi new file mode 100644 index 000000000000..bee8d41a2caf --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/include.gypi @@ -0,0 +1,53 @@ +# @license Apache-2.0 +# +# Copyright (c) 2026 The Stdlib Authors. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +# A GYP include file for building a Node.js native add-on. +# +# Main documentation: +# +# [1]: https://gyp.gsrc.io/docs/InputFormatReference.md +# [2]: https://gyp.gsrc.io/docs/UserDocumentation.md +{ + # Define variables to be used throughout the configuration for all targets: + 'variables': { + # Source directory: + 'src_dir': './src', + + # Include directories: + 'include_dirs': [ + '=0.10.0", + "npm": ">2.7.0" + }, + "os": [ + "aix", + "darwin", + "freebsd", + "linux", + "macos", + "openbsd", + "sunos", + "win32", + "windows" + ], + "keywords": [ + "stdlib", + "stdmath", + "statistics", + "stats", + "mathematics", + "math", + "standard deviation", + "variance", + "var", + "deviation", + "dispersion", + "spread", + "sample standard deviation", + "unbiased", + "stdev", + "std", + "nan", + "missing", + "omit", + "ignore", + "strided", + "strided array", + "typed", + "array", + "float32", + "float", + "single", + "float32array" + ], + "__stdlib__": {} +} diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/src/Makefile b/lib/node_modules/@stdlib/stats/strided/snanstdev/src/Makefile new file mode 100644 index 000000000000..2caf905cedbe --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/src/Makefile @@ -0,0 +1,70 @@ +#/ +# @license Apache-2.0 +# +# Copyright (c) 2026 The Stdlib Authors. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +#/ + +# VARIABLES # + +ifndef VERBOSE + QUIET := @ +else + QUIET := +endif + +# Determine the OS ([1][1], [2][2]). +# +# [1]: https://en.wikipedia.org/wiki/Uname#Examples +# [2]: http://stackoverflow.com/a/27776822/2225624 +OS ?= $(shell uname) +ifneq (, $(findstring MINGW,$(OS))) + OS := WINNT +else +ifneq (, $(findstring MSYS,$(OS))) + OS := WINNT +else +ifneq (, $(findstring CYGWIN,$(OS))) + OS := WINNT +else +ifneq (, $(findstring Windows_NT,$(OS))) + OS := WINNT +endif +endif +endif +endif + + +# RULES # + +#/ +# Removes generated files for building an add-on. +# +# @example +# make clean-addon +#/ +clean-addon: + $(QUIET) -rm -f *.o *.node + +.PHONY: clean-addon + +#/ +# Removes generated files. +# +# @example +# make clean +#/ +clean: clean-addon + +.PHONY: clean diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/src/addon.c b/lib/node_modules/@stdlib/stats/strided/snanstdev/src/addon.c new file mode 100644 index 000000000000..2fc032427cfe --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/src/addon.c @@ -0,0 +1,99 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +#include "stdlib/stats/strided/snanstdev.h" +#include "stdlib/napi/argv_int64.h" +#include "stdlib/napi/argv_float.h" +#include "stdlib/napi/argv_strided_float32array.h" +#include "stdlib/napi/create_double.h" +#include +#include + +/** +* Receives JavaScript callback invocation data. +* +* @param env environment under which the function is invoked +* @param info callback data +* @return Node-API value +*/ +static napi_value addon( napi_env env, napi_callback_info info ) { + STDLIB_NAPI_ARGV( env, info, argv, argc, 4 ); + STDLIB_NAPI_ARGV_INT64( env, N, argv, 0 ); + STDLIB_NAPI_ARGV_FLOAT( env, correction, argv, 1 ); + CBLAS_INT stride; + STDLIB_NAPI_ARGV_STRIDED_FLOAT32ARRAY( env, X, N, stride, argv, 2 ); + STDLIB_NAPI_ARGV_INT64( env, strideX, argv, 3 ); + double v = stdlib_strideXd_snanstdev( N, correction, X, stride ); + + napi_value out; + napi_status status = stdlib_napi_create_double( env, v, &out ); + assert( status == napi_ok ); + return out; +} + +/** +* Receives JavaScript callback invocation data for ndarray interface. +* +* @param env environment under which the function is invoked +* @param info callback data +* @return Node-API value +*/ +static napi_value addon_ndarray( napi_env env, napi_callback_info info ) { + STDLIB_NAPI_ARGV( env, info, argv, argc, 5 ); + STDLIB_NAPI_ARGV_INT64( env, N, argv, 0 ); + STDLIB_NAPI_ARGV_FLOAT( env, correction, argv, 1 ); + CBLAS_INT stride; + STDLIB_NAPI_ARGV_STRIDED_FLOAT32ARRAY( env, X, N, stride, argv, 2 ); + STDLIB_NAPI_ARGV_INT64( env, strideX, argv, 3 ); + STDLIB_NAPI_ARGV_INT64( env, offsetX, argv, 4 ); + double v = stdlib_strided_snanstdev_ndarray( N, correction, X, strideX, offsetX ); + + napi_value out; + napi_status status = stdlib_napi_create_double( env, v, &out ); + assert( status == napi_ok ); + return out; +} + +/** +* Initializes a Node-API module. +* +* @param env environment under which the function is invoked +* @param exports exports object +* @return main export +*/ +static napi_value init( napi_env env, napi_value exports ) { + napi_value fcn; + napi_status status; + + // Create the main function: + status = napi_create_function( env, "exports", NAPI_AUTO_LENGTH, addon, NULL, &fcn ); + assert( status == napi_ok ); + + // Create the ndarray function: + napi_value ndarray_fcn; + status = napi_create_function( env, "ndarray", NAPI_AUTO_LENGTH, addon_ndarray, NULL, &ndarray_fcn ); + assert( status == napi_ok ); + + // Set the ndarray property on the main function: + status = napi_set_named_property( env, fcn, "ndarray", ndarray_fcn ); + assert( status == napi_ok ); + + return fcn; +} + +NAPI_MODULE( NODE_GYP_MODULE_NAME, init ) diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/src/main.c b/lib/node_modules/@stdlib/stats/strided/snanstdev/src/main.c new file mode 100644 index 000000000000..11c42bf31a4e --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/src/main.c @@ -0,0 +1,48 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +#include "stdlib/stats/strided/snanstdev.h" +#include "stdlib/stats/base/snanstdevpn.h" +#include "stdlib/blas/base/shared.h" + +/** +* Computes the standard deviation of a single-precision floating-point strided array, ignoring NaN values. +* +* @param N number of indexed elements +* @param correction degrees of freedom adjustment +* @param X input array +* @param strideX stride length +* @return output value +*/ +float API_SUFFIX(stdlib_strided_snanstdev)( const CBLAS_INT N, const float correction, const float *X, const CBLAS_INT strideX ) { + return API_SUFFIX(stdlib_base_snanstdevpn)( N, correction, X, strideX ); +} + +/** +* Computes the standard deviation of a single-precision floating-point strided array, ignoring NaN values and using alternative indexing semantics. +* +* @param N number of indexed elements +* @param correction degrees of freedom adjustment +* @param X input array +* @param strideX stride length +* @param offsetX starting index for X +* @return output value +*/ +float API_SUFFIX(stdlib_strided_snanstdev_ndarray)( const CBLAS_INT N, const float correction, const float *X, const CBLAS_INT strideX, const CBLAS_INT offsetX ) { + return API_SUFFIX(stdlib_base_snanstdevpn_ndarray)( N, correction, X, strideX, offsetX ); +} diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.js b/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.js new file mode 100644 index 000000000000..8ba80fc765c2 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.js @@ -0,0 +1,97 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +'use strict'; + +// MODULES // + +var tape = require( 'tape' ); +var isnan = require( '@stdlib/math/base/assert/is-nan' ); +var Float32Array = require( '@stdlib/array/float32' ); +var snanstdev = require( './../lib' ); + + +// TESTS // + +tape( 'main export is a function', function test( t ) { + t.ok( true, __filename ); + t.strictEqual( typeof snanstdev, 'function', 'main export is a function' ); + t.end(); +}); + +tape( 'the function has an arity of 4', function test( t ) { + t.strictEqual( snanstdev.length, 4, 'has expected arity' ); + t.end(); +}); + +tape( 'the function calculates the standard deviation of a strided array, ignoring NaN values', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, NaN, 5.0, 0.0, 3.0 ] ); + v = snanstdev( x.length, 1, x, 1 ); + t.strictEqual( typeof v, 'number', 'returns a number' ); + + x = new Float32Array( [ -4.0, NaN, -4.0 ] ); + v = snanstdev( x.length, 1, x, 1 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + x = new Float32Array( [ NaN, 4.0 ] ); + v = snanstdev( x.length, 1, x, 1 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + t.end(); +}); + +tape( 'if provided an `N` parameter less than or equal to `0`, the function returns `NaN`', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( 0, 1, x, 1 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + v = snanstdev( -1, 1, x, 1 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + t.end(); +}); + +tape( 'if provided a `stride` parameter equal to `0`, the function returns `0` if the first element is not NaN', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( x.length, 1, x, 0 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports an `ndarray` method which calculates the standard deviation using alternative indexing semantics', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, NaN, -4.0, 5.0, 0.0, 3.0 ] ); + v = snanstdev.ndarray( x.length, 1, x, 1, 0 ); + t.strictEqual( typeof v, 'number', 'returns a number' ); + + t.end(); +}); diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.ndarray.js b/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.ndarray.js new file mode 100644 index 000000000000..8da9cb05c0e6 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.ndarray.js @@ -0,0 +1,158 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +'use strict'; + +// MODULES // + +var tape = require( 'tape' ); +var isnan = require( '@stdlib/math/base/assert/is-nan' ); +var Float32Array = require( '@stdlib/array/float32' ); +var snanstdev = require( './../lib/ndarray.js' ); + + +// TESTS // + +tape( 'main export is a function', function test( t ) { + t.ok( true, __filename ); + t.strictEqual( typeof snanstdev, 'function', 'main export is a function' ); + t.end(); +}); + +tape( 'the function has an arity of 5', function test( t ) { + t.strictEqual( snanstdev.length, 5, 'has expected arity' ); + t.end(); +}); + +tape( 'the function calculates the standard deviation of a strided array, ignoring NaN values', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, NaN, 5.0, 0.0, 3.0 ] ); + v = snanstdev( x.length, 1, x, 1, 0 ); + t.strictEqual( typeof v, 'number', 'returns a number' ); + + x = new Float32Array( [ -4.0, NaN, -4.0 ] ); + v = snanstdev( x.length, 1, x, 1, 0 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + x = new Float32Array( [ NaN, 4.0 ] ); + v = snanstdev( x.length, 1, x, 1, 0 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports an `offset` parameter', function test( t ) { + var x; + var v; + + x = new Float32Array([ + 2.0, + 1.0, // 0 + 2.0, + -2.0, // 1 + -2.0, + 2.0, // 2 + 3.0, + 4.0, // 3 + NaN, // 4 + NaN + ]); + + v = snanstdev( 5, 1, x, 2, 1 ); + t.strictEqual( v, 2.5, 'returns expected value' ); + + t.end(); +}); + +tape( 'if provided an `N` parameter less than or equal to `0`, the function returns `NaN`', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( 0, 1, x, 1, 0 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + v = snanstdev( -1, 1, x, 1, 0 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + t.end(); +}); + +tape( 'if provided a `stride` parameter equal to `0`, the function returns `0` if the indexed element is not NaN', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( x.length, 1, x, 0, 0 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports negative strides', function test( t ) { + var x; + var v; + + x = new Float32Array([ + NaN, // 4 + NaN, + 1.0, // 3 + 2.0, + 2.0, // 2 + -7.0, + -2.0, // 1 + 3.0, + 4.0, // 0 + 2.0 + ]); + + v = snanstdev( 5, 1, x, -2, 8 ); + t.strictEqual( v, 2.5, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports view offsets', function test( t ) { + var x0; + var x1; + var v; + + x0 = new Float32Array([ + 2.0, + 1.0, // 0 + 2.0, + -2.0, // 1 + -2.0, + 2.0, // 2 + 3.0, + 4.0, // 3 + NaN, // 4 + NaN + ]); + + x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element + + v = snanstdev( 5, 1, x1, 2, 0 ); + t.strictEqual( v, 2.5, 'returns expected value' ); + + t.end(); +}); diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.ndarray.native.js b/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.ndarray.native.js new file mode 100644 index 000000000000..ced386514097 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.ndarray.native.js @@ -0,0 +1,155 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +'use strict'; + +// MODULES // + +var resolve = require( 'path' ).resolve; +var tape = require( 'tape' ); +var isnan = require( '@stdlib/math/base/assert/is-nan' ); +var Float32Array = require( '@stdlib/array/float32' ); +var tryRequire = require( '@stdlib/utils/try-require' ); + + +// VARIABLES // + +var snanstdev = tryRequire( resolve( __dirname, './../lib/ndarray.native.js' ) ); +var opts = { + 'skip': ( snanstdev instanceof Error ) +}; + + +// TESTS // + +tape( 'main export is a function', opts, function test( t ) { + t.ok( true, __filename ); + t.strictEqual( typeof snanstdev, 'function', 'main export is a function' ); + t.end(); +}); + +tape( 'the function has an arity of 5', opts, function test( t ) { + t.strictEqual( snanstdev.length, 5, 'has expected arity' ); + t.end(); +}); + +tape( 'the function calculates the standard deviation of a strided array, ignoring NaN values', opts, function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, NaN, 5.0, 0.0, 3.0 ] ); + v = snanstdev( x.length, 1, x, 1, 0 ); + t.strictEqual( typeof v, 'number', 'returns a number' ); + + x = new Float32Array( [ -4.0, NaN, -4.0 ] ); + v = snanstdev( x.length, 1, x, 1, 0 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + x = new Float32Array( [ NaN, 4.0 ] ); + v = snanstdev( x.length, 1, x, 1, 0 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports an `offset` parameter', opts, function test( t ) { + var x; + var v; + + x = new Float32Array([ + 2.0, + 1.0, // 0 + 2.0, + -2.0, // 1 + -2.0, + 2.0, // 2 + 3.0, + 4.0, // 3 + NaN, // 4 + NaN + ]); + + v = snanstdev( 5, 1, x, 2, 1 ); + t.strictEqual( v, 2.5, 'returns expected value' ); + + t.end(); +}); + +tape( 'if provided an `N` parameter less than or equal to `0`, the function returns `NaN`', opts, function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( 0, 1, x, 1, 0 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + v = snanstdev( -1, 1, x, 1, 0 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports negative strides', opts, function test( t ) { + var x; + var v; + + x = new Float32Array([ + NaN, // 4 + NaN, + 1.0, // 3 + 2.0, + 2.0, // 2 + -7.0, + -2.0, // 1 + 3.0, + 4.0, // 0 + 2.0 + ]); + + v = snanstdev( 5, 1, x, -2, 8 ); + t.strictEqual( v, 2.5, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports view offsets', opts, function test( t ) { + var x0; + var x1; + var v; + + x0 = new Float32Array([ + 2.0, + 1.0, // 0 + 2.0, + -2.0, // 1 + -2.0, + 2.0, // 2 + 3.0, + 4.0, // 3 + NaN, // 4 + NaN + ]); + + x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element + + v = snanstdev( 5, 1, x1, 2, 0 ); + t.strictEqual( v, 2.5, 'returns expected value' ); + + t.end(); +}); diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.snanstdev.js b/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.snanstdev.js new file mode 100644 index 000000000000..716b19b88405 --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.snanstdev.js @@ -0,0 +1,228 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +'use strict'; + +// MODULES // + +var tape = require( 'tape' ); +var sqrt = require( '@stdlib/math/base/special/sqrt' ); +var abs = require( '@stdlib/math/base/special/abs' ); +var isnan = require( '@stdlib/math/base/assert/is-nan' ); +var float64ToFloat32 = require( '@stdlib/number/float64/base/to-float32' ); +var EPS = require( '@stdlib/constants/float32/eps' ); +var Float32Array = require( '@stdlib/array/float32' ); +var snanstdev = require( './../lib/snanstdev.js' ); + + +// TESTS // + +tape( 'main export is a function', function test( t ) { + t.ok( true, __filename ); + t.strictEqual( typeof snanstdev, 'function', 'main export is a function' ); + t.end(); +}); + +tape( 'the function has an arity of 4', function test( t ) { + t.strictEqual( snanstdev.length, 4, 'has expected arity' ); + t.end(); +}); + +tape( 'the function calculates the population standard deviation of a strided array, ignoring NaN values', function test( t ) { + var expected; + var delta; + var tol; + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, 5.0, NaN, 0.0, 3.0 ] ); + v = snanstdev( x.length, 0, x, 1 ); + + expected = float64ToFloat32( sqrt( 53.5/6 ) ); + delta = abs( v - expected ); + tol = 2.0 * EPS * abs( expected ); + t.strictEqual( delta <= tol, true, 'within tolerance. Actual: '+v+'. E: '+expected+'. tol: '+tol+'. Δ: '+delta+'.' ); + + x = new Float32Array( [ -4.0, NaN, -4.0 ] ); + v = snanstdev( x.length, 0, x, 1 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + x = new Float32Array( [ NaN, NaN ] ); + v = snanstdev( x.length, 0, x, 1 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function calculates the sample standard deviation of a strided array, ignoring NaN values', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, NaN, -4.0, 5.0, 0.0, 3.0 ] ); + v = snanstdev( x.length, 1, x, 1 ); + t.strictEqual( v, float64ToFloat32( sqrt( 53.5/5 ) ), 'returns expected value' ); + + x = new Float32Array( [ -4.0, NaN, -4.0 ] ); + v = snanstdev( x.length, 1, x, 1 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + x = new Float32Array( [ NaN, NaN ] ); + v = snanstdev( x.length, 1, x, 1 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + t.end(); +}); + +tape( 'if provided an `N` parameter less than or equal to `0`, the function returns `NaN`', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( 0, 1, x, 1 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + v = snanstdev( -1, 1, x, 1 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + t.end(); +}); + +tape( 'if provided an `N` parameter equal to `1` and a correction of `0`, the function returns a population standard deviation of `0`', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( 1, 0, x, 1 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + t.end(); +}); + +tape( 'if provided a `correction` parameter yielding `n-correction` less than or equal to `0` (where `n` is number of non-NaN elements), the function returns `NaN`', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, NaN, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( x.length, 5, x, 1 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + v = snanstdev( x.length, 6, x, 1 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports a `stride` parameter', function test( t ) { + var x; + var v; + + x = new Float32Array([ + 1.0, // 0 + 2.0, + 2.0, // 1 + -7.0, + -2.0, // 2 + 3.0, + 4.0, // 3 + 2.0, + NaN, // 4 + NaN + ]); + + v = snanstdev( 5, 1, x, 2 ); + + t.strictEqual( v, 2.5, 'returns expected value' ); + t.end(); +}); + +tape( 'the function supports a negative `stride` parameter', function test( t ) { + var x; + var v; + + x = new Float32Array([ + NaN, // 4 + NaN, + 1.0, // 3 + 2.0, + 2.0, // 2 + -7.0, + -2.0, // 1 + 3.0, + 4.0, // 0 + 2.0 + ]); + + v = snanstdev( 5, 1, x, -2 ); + + t.strictEqual( v, 2.5, 'returns expected value' ); + t.end(); +}); + +tape( 'if provided a `stride` parameter equal to `0`, the function returns `0` if the first element is not NaN', function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( x.length, 1, x, 0 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + t.end(); +}); + +tape( 'if provided a `stride` parameter equal to `0`, the function returns `NaN` if the first element is NaN', function test( t ) { + var x; + var v; + + x = new Float32Array( [ NaN, -2.0, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( x.length, 1, x, 0 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports view offsets', function test( t ) { + var x0; + var x1; + var v; + + x0 = new Float32Array([ + 2.0, + 1.0, // 0 + 2.0, + -2.0, // 1 + -2.0, + 2.0, // 2 + 3.0, + 4.0, // 3 + 6.0, + NaN, // 4 + NaN + ]); + + x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element + + v = snanstdev( 5, 1, x1, 2 ); + t.strictEqual( v, 2.5, 'returns expected value' ); + + t.end(); +}); diff --git a/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.snanstdev.native.js b/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.snanstdev.native.js new file mode 100644 index 000000000000..84f530ceb3ed --- /dev/null +++ b/lib/node_modules/@stdlib/stats/strided/snanstdev/test/test.snanstdev.native.js @@ -0,0 +1,168 @@ +/** +* @license Apache-2.0 +* +* Copyright (c) 2026 The Stdlib Authors. +* +* Licensed under the Apache License, Version 2.0 (the "License"); +* you may not use this file except in compliance with the License. +* You may obtain a copy of the License at +* +* http://www.apache.org/licenses/LICENSE-2.0 +* +* Unless required by applicable law or agreed to in writing, software +* distributed under the License is distributed on an "AS IS" BASIS, +* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +* See the License for the specific language governing permissions and +* limitations under the License. +*/ + +'use strict'; + +// MODULES // + +var resolve = require( 'path' ).resolve; +var tape = require( 'tape' ); +var isnan = require( '@stdlib/math/base/assert/is-nan' ); +var Float32Array = require( '@stdlib/array/float32' ); +var tryRequire = require( '@stdlib/utils/try-require' ); + + +// VARIABLES // + +var snanstdev = tryRequire( resolve( __dirname, './../lib/snanstdev.native.js' ) ); +var opts = { + 'skip': ( snanstdev instanceof Error ) +}; + + +// TESTS // + +tape( 'main export is a function', opts, function test( t ) { + t.ok( true, __filename ); + t.strictEqual( typeof snanstdev, 'function', 'main export is a function' ); + t.end(); +}); + +tape( 'the function has an arity of 4', opts, function test( t ) { + t.strictEqual( snanstdev.length, 4, 'has expected arity' ); + t.end(); +}); + +tape( 'the function calculates the standard deviation of a strided array, ignoring NaN values', opts, function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, NaN, 5.0, 0.0, 3.0 ] ); + v = snanstdev( x.length, 1, x, 1 ); + t.strictEqual( typeof v, 'number', 'returns a number' ); + + x = new Float32Array( [ -4.0, NaN, -4.0 ] ); + v = snanstdev( x.length, 1, x, 1 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + x = new Float32Array( [ NaN, 4.0 ] ); + v = snanstdev( x.length, 1, x, 1 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + t.end(); +}); + +tape( 'if provided an `N` parameter less than or equal to `0`, the function returns `NaN`', opts, function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( 0, 1, x, 1 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + v = snanstdev( -1, 1, x, 1 ); + t.strictEqual( isnan( v ), true, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports a `stride` parameter', opts, function test( t ) { + var x; + var v; + + x = new Float32Array([ + 1.0, // 0 + 2.0, + 2.0, // 1 + -7.0, + -2.0, // 2 + 3.0, + 4.0, // 3 + 2.0, + NaN, // 4 + NaN + ]); + + v = snanstdev( 5, 1, x, 2 ); + t.strictEqual( v, 2.5, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports a negative `stride` parameter', opts, function test( t ) { + var x; + var v; + + x = new Float32Array([ + NaN, // 4 + NaN, + 1.0, // 3 + 2.0, + 2.0, // 2 + -7.0, + -2.0, // 1 + 3.0, + 4.0, // 0 + 2.0 + ]); + + v = snanstdev( 5, 1, x, -2 ); + t.strictEqual( v, 2.5, 'returns expected value' ); + + t.end(); +}); + +tape( 'if provided a `stride` parameter equal to `0`, the function returns `0` if the first element is not NaN', opts, function test( t ) { + var x; + var v; + + x = new Float32Array( [ 1.0, -2.0, -4.0, 5.0, 3.0 ] ); + + v = snanstdev( x.length, 1, x, 0 ); + t.strictEqual( v, 0.0, 'returns expected value' ); + + t.end(); +}); + +tape( 'the function supports view offsets', opts, function test( t ) { + var x0; + var x1; + var v; + + x0 = new Float32Array([ + 2.0, + 1.0, // 0 + 2.0, + -2.0, // 1 + -2.0, + 2.0, // 2 + 3.0, + 4.0, // 3 + 6.0, + NaN, // 4 + NaN + ]); + + x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element + + v = snanstdev( 5, 1, x1, 2 ); + t.strictEqual( v, 2.5, 'returns expected value' ); + + t.end(); +});