assigning to vectors within bsxfun

I do not know why this operation throws an error in bsxfun

c3 = bsxfun(@(x,y,z,m,op) x(1:y(:),:) = z(1:op:op*y(:),1) + m(:), X, Y, Z, M, Option);

The loop I am trying to vectorize is this :

for k=1:Count
  X(1:Y(k),k)= Z(1: Option: Option* Y(k),1) + M(k);
end

what am I doing wrong?

[Jan]

I'm interested in a comparison of the runtimes. I do not see a benefit for the vectorized versions at first glance.

Answer 1

[Andrei Bobrov]

Z1 = bsxfun(@plus,Z(1:op:op*max(Y)),M(:).');
s = size(Z1);
Z2 = zeros(s);
Z2(sub2ind(s,Y,1:s(2))) = 1;
x = Z1.*flipud(cumsum(flipud(Z2)));