'Add a multiple of vector vec to every row of the matrix. If a target
is provided, it is used to store the result instead of self.'

def add_row_mult(self, vec, mult, target=None):

    if (not target):
        target = self
    err_code = _eigenmat.add_row_mult(self.p_mat, vec.p_mat, target.p_mat, ct.c_float(mult))
    if err_code:
        raise generate_exception(err_code)
    return target
