Uses convex optimization via the CVXR-package to find a matrix \(M\) that maximizes the entropy function
where \(M\) satisfies the following constraints:
(1) the values of \(M\) are between 0 & 1, (2) the row sums of the matrix
are equal to the row sums of the original matrix, (3) the column sums of the matrix
are equal to the column sums of the original matrix.
This method is utilized in the function sdsm to compute probabilities of an edge existing in a graph.
Method is called polytope as it is optimizing over the convex hull of the set of matrices (thought of as vectors) with
the same row and column sums as the input.