< row indices, size nzmax starting from 0
< number of rows
< number of columns
< number of entries in triplet matrix, -1 for csc
< maximum number of entries
< column pointers (size n+1); col indices (size nzmax) start from 0 when using triplet format (direct KKT matrix formation)
< numerical values, size nzmax
Matrix in compressed-column form. The structure is used internally to store matrices in the triplet form as well, but the API requires that the matrices are in the CSC format.