(S|D|C|Z)POTRS
==============
Single, double, single complex, and double complex POTRS.

Description
-----------
Solves a system of linear equations for multiple right-hand sides
given the Cholesky factorization of the matrix.

Solves:

.. math::

    A \mult X = B

If UPLO is 'U' then A has been factored using an upper triangular matrix U:

.. math::

    A = \herm{U} \mult U

If UPLO is 'L' then A has been factored using a lower triangular matrix L:

.. math::

    A = L \mult \herm{L}

The factored form is used to solve the system of equations. Only the
upper or lower triangular part of A is referenced.

To get the Cholesky factorization of a matrix use :doc:`POTRF<potrf>`.


LAPACK Interface
----------------
.. code-block:: c

    void spotrs(const char *UPLO, const qml_long *N, const qml_long *NRHS, float *A,
        const qml_long *LDA, float *B, const qml_long *LDB, qml_long *INFO);

    void dpotrs(const char *UPLO, const qml_long *N, const qml_long *NRHS, double *A,
        const qml_long *LDA, double *B, const qml_long *LDB, qml_long *INFO);

    void cpotrs(const char *UPLO, const qml_long *N, const qml_long *NRHS,
        qml_single_complex *A, const qml_long *LDA, qml_single_complex *B,
        const qml_long *LDB, qml_long *INFO);

    void zpotrs(const char *UPLO, const qml_long *N, const qml_long *NRHS,
        qml_double_complex *A, const qml_long *LDA, qml_double_complex *B,
        const qml_long *LDB, qml_long *INFO);


Arguments
---------
======   =====================================================================
UPLO     Specify whether A has been factored in 'U' upper triangular or 'L' lower triangular form
N        Number of linear equations, order of the matrix A
NRHS     Number of right hand sides, number of columns of B
A        Matrix of size N x N in factored form
LDA      Leading dimension of A
B        On entry, the N x NRHS matrix B, on exit the solution matrix
LDB      Leading dimension of B
INFO     0 on success, <0 on illegal arguments
======   =====================================================================
