Converts distance objects into similarity objects.
dist2sim(dist, transform, k = 1, normalise = TRUE, max_d)dist2sim(x) returns an object of class similarity.
Distances can be transformed either *linearly* or *exponentially*. That is
1 - k * dist for non-negative values, or exp(-k * dist),
respectively. If normalise is true, then dist = dist/max_d.