stat/mds: add warning about ED numerical stability
@@ -14,6 +14,8 @@ import (
// TorgersonScaling converts a dissimilarity matrix to a matrix containing
// Euclidean coordinates. TorgersonScaling places the coordinates in dst and
// returns it and the number of positive Eigenvalues if successful.
+// Note that Eigen Decomposition is numerically unstable and so Eigenvalues
+// near zero should be examined and the value returned for k is advisory only.
// If the scaling is not successful, dst will be empty upon return.
// When the scaling is successful, dst will be resized to k columns wide.
// Eigenvalues will be copied into eigdst and returned as eig if it is provided.
