B must have the same number of rows as A. Cannot return S when B contains multiple right-hand sides. Inputs may not be sparse for the ''orth'' algorithm. V must be positive definite if sparse. V is rank deficient to within machine precision - switching to orthogonal algorithm. V must be positive definite or positive semidefinite. V must be a {0, number, integer}-by-{1, number, integer} covariance matrix or a {2, number, integer}-by-1 weight vector. A is rank deficient to within machine precision. T is orthogonal to the null space of A. B is not consistent with A and V. One or more columns of B are not consistent with A and V. ALG must be ''chol'' or ''orth''. V must be symmetric. Some columns of T are orthogonal to the null space of A.