I am learning PHP, and a problem has arisen me, I have a matrix, I order by a field we say it sport, and soon classified already by sport I want to order it per dates so that it orders within each group per dates. I cannot do it on the same matrix because I return it to disorder, is possible to be created another matrix in the style of array_push, where it stores a part to me of the matrix and has already I order it?. That is to say, a matrix that depends on another one.