Suppose my VRPLIB file has the following section:
NODE_SECTION
1 40 50
3 20 20
2 20 10
VRPLIB parses this as [[40, 50], [20, 20], [20, 10]], which ignores that the third and second node are provided in a different order in the data file. Thus, the parsed data are subtly wrong.
Additionally, the following
NODE_SECTION
1 40 50
2 20 20
4 20 10
is parsed in the same manner, despite node 3 never having been specified.
If we reindex the data based on the node indices, we get the correct order for free, and additionally, the second example will raise about 4 being out of range for the actual data. That means such an issue no longer fails silently.
Suppose my VRPLIB file has the following section:
VRPLIB parses this as
[[40, 50], [20, 20], [20, 10]], which ignores that the third and second node are provided in a different order in the data file. Thus, the parsed data are subtly wrong.Additionally, the following
is parsed in the same manner, despite node 3 never having been specified.
If we reindex the data based on the node indices, we get the correct order for free, and additionally, the second example will raise about
4being out of range for the actual data. That means such an issue no longer fails silently.