4D array with only elements on one side of the diagonal

[schniefen]

Given the parameters n and m, I'd like to initialize a n x n4D array where each entry is an m x m matrix, and where each column of the matrix is an array of type numpy.linspace(0,1,m). Furthermore, I'd only like to have entries on the diagonal and above it, or only on the diagonal and below it. Is there a possible one-liner for this?