I don't see why in Julia or Matlab you would want to use repmat or broadcasting. For me, the following simple line of code:
m,n,p = size(A) reshape(reshape(A,m*n,p)*y,(m,n)) accomplishes your task, and it has about the same speed as matrixLinComb2. It writes it as a simple multiplication so it can use BLAS and vectorisation etc.
