samer@4: function [Y,Z]=divnorm(F,X)
samer@4: % divnorm - Do divisive normalisation of a sequence of vectors.
samer@4: %
samer@4: % divnorm ::
samer@4: %    ([[N,L]] -> [[1,L]]) ~'function to compute norm',
samer@4: %    [[N,L]]    ~'array of L N-dim vectors'
samer@4: % -> [[N,L]]    ~'normalised vectors (ie unit 2-norm)',
samer@4: %    [[1,L]]    ~'array of normalisation factors'.
samer@4: %
samer@4: % ie, if [Y,Z]=divnorm(X),
samer@4: % then X = repmat(Z,size(X,1),1).*Y
samer@4: %
samer@4: % TODO: might like to smooth the envelope before dividing.
samer@4: Y = vecop1(@rdivide,X,F(X));
samer@4: