Here's my problem:
I have a vector and I want to convert it into a matrix with fixed number of columns, but I don't want to replicate the vector to fill the matrix when it's necessary.
For example:
My vector has a length of 15, and I want a matrix with 4 columns.I wish to get the matrix wit 15 elements from the vector and a 0 for the last element in the matrix.
How can I do this? 

Edit:
Sorry for not stating the question clearly and misguiding you guys with my example. In my program,**I don't know the length of my vector, it depends on other parameters and this question involves with a loop, so I need a general solution that can solve many different cases, not just my example.**
Thanks for answering.