R Mirra Project

[stemir99-commits]

These functions create a special matrix object that can store a matrix

and cache its inverse, avoiding repeated and costly recalculations

if the matrix hasn't changed.

makeCacheMatrix creates a special "matrix" object, which is actually a list

containing four functions to: set the matrix, get the matrix,

set the inverse, and get the inverse.

makeCacheMatrix <- function(x = matrix()) {
inv <- NULL # This will store the cached inverse (initially empty)

    # 1. Function to set a new matrix
    set <- function(y) {
            x <<- y       # Assigns the value to 'x' in the parent environment
            inv <<- NULL  # Resets the cached inverse to NULL if the matrix changes
    }
    
    # 2. Function to get the current matrix
    get <- function() x
    
    # 3. Function to save the calculated inverse to the cache
    setInverse <- function(inverse) inv <<- inverse
    
    # 4. Function to retrieve the inverse from the cache
    getInverse <- function() inv
    
    # Returns a list containing the 4 functions defined above
    list(set = set, get = get,
         setInverse = setInverse,
         getInverse = getInverse)

}

cacheSolve computes the inverse of the special "matrix" returned by makeCacheMatrix.

If the inverse has already been calculated (and the matrix hasn't changed),

it retrieves the result directly from the cache, skipping the computation.

cacheSolve <- function(x, ...) {
## Check if the inverse is already present in the cache
inv <- x$getInverse()

    ## If it exists (is not NULL), return the message and the cached value
    if(!is.null(inv)) {
            message("getting cached data")
            return(inv)
    }
    
    ## If it does NOT exist, get the original matrix...
    data <- x$get()
    
    ## ...calculate the inverse using the solve() function...
    inv <- solve(data, ...)
    
    ## ...save the calculated inverse to the object's cache...
    x$setInverse(inv)
    
    ## ...and finally return the inverse matrix
    inv

}