annotate general/numerical/scalar/safe_exp.m @ 61:eff6bddf82e3 tip

Finally implemented perceptual brightness thing.

function [y,k]=safe_exp(x,l)
% safe_exp - high dynamic range exponential
%
% safe_exp :: X:[[N,M]] -> [[N,M]], [[1,M]].
%
% returns y and k such that exp(X) = y * exp(k) and
% maximum value in y is 1.

k=max(x,[],1);
y=exp(x-repmat(k,size(x,1),1));