[Haskell-cafe] Coplanarity or Colinearity [Was: low-cost matrix rank?]

[Mike Meyer]

Well, none of the suggested solutions for computing the rank of a matrix
really suited my needs, as dragging in something like BLAS introduce more
cost than just integrating the bed-and-breakfast library into my own
library. So let me try a different track.

My real problem is that I've got a list of points in R3  and want to decide
if they determine a plane, meaning they are coplanar but not colinear.
Similarly, given a list of points in R2, I want to verify that they aren't
colinear. Both of these can be done by converting the list of points to a
matrix and finding the rank of the matrix, but I only use the rank function
in the definitions of colinear and coplanar.

Maybe there's an easier way to tackle the underlying problems. Anyone got a
suggestion for such?
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