samer@4: function Y=mapcols(f,X)
samer@4: % mapcols - Map a function of a vector over the columns of an array
samer@4: %
samer@4: % mapcols :: 
samer@4: %    ([[N]->A] -> [[M]->B]) ~'function maps a column of A to one of B',
samer@4: %    [[N,L]->A]
samer@4: % -> [[M,L]->B].
samer@4: 
samer@4: n=size(X,2);
samer@4: if n==0, Y=[];
samer@4: else
samer@12: 	y1=f(X(:,1)); 
samer@12: 	if size(y1,2)>1
samer@12: 		Y=repmat(y1(:),1,n);
samer@12: 		for i=2:n
samer@12: 			Y(:,i)=flatten(f(flatten(X(:,i))));
samer@12: 		end
samer@12: 	else
samer@12: 		Y=repmat(y1,1,n);
samer@12: 		for i=2:n, Y(:,i)=f(X(:,i)); end
samer@4: 	end
samer@4: end
samer@4: