wkeep [y]=wkeep(x,l) [y]=wkeep(x,l,opt) x: Real, complex or string type input vector or matrix l: Length of matrix required opt: Character input to determine which side to extract from This is an Octave function [y]=wkeep(x,l) extracts a vector of length l from the centre of input vector x. [y]=wkeep(x,l,opt) extracts vector based on opt which could be 'l','r' or 'c' (left, right or central).