Matlab's bsxfun() code

Question

What does this do?

u = [5 6];
s = [1 1];
data1    =[randn(10,1) -1*ones(10,1)];
data2    =[randn(10,1) ones(10,1)];
data     = [data1; data2];
deviance = bsxfun(         


        

Answer 1

bsxfun does binary operations element wise. It's useful when you need to subtract a vector (in this case u) from all the elements along a particular dimension in a matrix (in this case data). The dimension along which the operation is being performed must match in both cases. For your example, you can incorporate the code without bsxfun as

u1=repmat(u,size(data,2),1);
deviance=data-u1;

and so on for the other operations.