-"""
+r"""
The doubly-nonnegative cone in `S^{n}` is the set of all such matrices
that both,
def is_admissible_extreme_rank(r, n):
- """
+ r"""
The extreme matrices of the doubly-nonnegative cone have some
restrictions on their ranks. This function checks to see whether the
rank ``r`` would be an admissible rank for an ``n``-by-``n`` matrix.
"""
- if not is_admissible_extreme_rank(rank, V.dimension()):
+ if rank is not None and not is_admissible_extreme_rank(rank, V.dimension()):
msg = 'Rank %d not possible in dimension %d.'
raise ValueError(msg % (rank, V.dimension()))