Provided by: liblapack-doc_3.3.1-1_all bug

NAME

       LAPACK-3 - computes the solution to a real system of linear equations  A * X = B,

SYNOPSIS

       SUBROUTINE SGESV( N, NRHS, A, LDA, IPIV, B, LDB, INFO )

           INTEGER       INFO, LDA, LDB, N, NRHS

           INTEGER       IPIV( * )

           REAL          A( LDA, * ), B( LDB, * )

PURPOSE

       SGESV computes the solution to a real system of linear equations
          A * X = B,
        where A is an N-by-N matrix and X and B are N-by-NRHS matrices.
        The LU decomposition with partial pivoting and row interchanges is
        used to factor A as
           A = P * L * U,
        where P is a permutation matrix, L is unit lower triangular, and U is
        upper triangular.  The factored form of A is then used to solve the
        system of equations A * X = B.

ARGUMENTS

        N       (input) INTEGER
                The number of linear equations, i.e., the order of the
                matrix A.  N >= 0.

        NRHS    (input) INTEGER
                The number of right hand sides, i.e., the number of columns
                of the matrix B.  NRHS >= 0.

        A       (input/output) REAL array, dimension (LDA,N)
                On entry, the N-by-N coefficient matrix A.
                On exit, the factors L and U from the factorization
                A = P*L*U; the unit diagonal elements of L are not stored.

        LDA     (input) INTEGER
                The leading dimension of the array A.  LDA >= max(1,N).

        IPIV    (output) INTEGER array, dimension (N)
                The pivot indices that define the permutation matrix P;
                row i of the matrix was interchanged with row IPIV(i).

        B       (input/output) REAL array, dimension (LDB,NRHS)
                On entry, the N-by-NRHS matrix of right hand side matrix B.
                On exit, if INFO = 0, the N-by-NRHS solution matrix X.

        LDB     (input) INTEGER
                The leading dimension of the array B.  LDB >= max(1,N).

        INFO    (output) INTEGER
                = 0:  successful exit
                < 0:  if INFO = -i, the i-th argument had an illegal value
                > 0:  if INFO = i, U(i,i) is exactly zero.  The factorization
                has been completed, but the factor U is exactly
                singular, so the solution could not be computed.

 LAPACK driver routine (version 3.2)        April 2011                             SGESV(3lapack)