'Delete the given row of the matrix.
Examples
>>> from sympy.matrices import SparseMatrix
>>> M = SparseMatrix([[0, 0], [0, 1]])
>>> M
Matrix([
[0, 0],
[0, 1]])
>>> M.row_del(0)
>>> M
Matrix([[0, 1]])
See Also
col_del'

def row_del(self, k):

    newD = {}
    k = a2idx(k, self.rows)
    for (i, j) in self._smat:
        if (i == k):
            pass
        elif (i > k):
            newD[((i - 1), j)] = self._smat[(i, j)]
        else:
            newD[(i, j)] = self._smat[(i, j)]
    self._smat = newD
    self.rows -= 1
