Introduction - If you have any usage issues, please Google them yourself
If A is a matrix of mxn Rank (A) = r.
A decomposition mxr full rank matrix X and the product of the rxn full rank matrix Y, A = XY and rank (X) = rank (Y) = rank (A) = r, this decomposition is called full rank decomposition, of course, is not unique when r> 0 full rank decomposition.