I don't know if there's another term for the type of linear transform that collapses all points onto a line or the origin, but my book calls it a "flattening", and I'm wondering how you can tell if a transform is of a flattening type?
The book I have says if one column of the matrix for the transform is a "scalar multiple" of the other, then it's flattening. Not quite sure what that means, however the example uses the matrix:
And says the columns have a difference of 2/3 which means it's flattening, which confuses me as I thought scalar meant a whole integer? Any help/hints in this would be massively appreciated!!