matthiasm@8: function y=max_mult(A,x)
matthiasm@8: % MAX_MULT Like matrix multiplication, but sum gets replaced by max
matthiasm@8: % function y=max_mult(A,x) y(i) = max_j A(i,j) x(j)
matthiasm@8: 
matthiasm@8: %X=ones(size(A,1),1) * x(:)'; % X(j,i) = x(i)
matthiasm@8: %y=max(A.*X, [], 2);
matthiasm@8: 
matthiasm@8: % This is faster
matthiasm@8: if size(x,2)==1
matthiasm@8:   X=x*ones(1,size(A,1)); % X(i,j) = x(i)
matthiasm@8:   y=max(A'.*X)';
matthiasm@8: else
matthiasm@8: %this works for arbitrarily sized A and x (but is ugly, and slower than above)
matthiasm@8:   X=repmat(x, [1 1 size(A,1)]);
matthiasm@8:   B=repmat(A, [1 1 size(x,2)]);
matthiasm@8:   C=permute(B,[2 3 1]);
matthiasm@8:   y=permute(max(C.*X),[3 2 1]);
matthiasm@8: %  this is even slower, as is using squeeze instead of permute
matthiasm@8: %  Y=permute(X, [3 1 2]);
matthiasm@8: %  y=permute(max(Y.*B, [], 2), [1 3 2]);
matthiasm@8: end