A super-fast algorithm for matching two sets of polylines and showing the difference. Primarily used for comparing road networks from different datasets.
Given arrays a and b, like linematch(a, b, 0.001), linematch will return a new
array that contains all segments in a that are not matched with segments in b.
If the arrays match exactly, the returned value will be an empty array, [].
// given two arrays of linestrings and a threshold value,
// outputs a difference as an array of linestrings
var result = linematch(lines1, lines2, 0.0001);