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

NAME

       LAPACK-3 - reduces a real symmetric-definite generalized eigenproblem to standard form

SYNOPSIS

       SUBROUTINE SSYGST( ITYPE, UPLO, N, A, LDA, B, LDB, INFO )

           CHARACTER      UPLO

           INTEGER        INFO, ITYPE, LDA, LDB, N

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

PURPOSE

       SSYGST reduces a real symmetric-definite generalized eigenproblem to standard form.
        If ITYPE = 1, the problem is A*x = lambda*B*x,
        and A is overwritten by inv(U**T)*A*inv(U) or inv(L)*A*inv(L**T)
        If ITYPE = 2 or 3, the problem is A*B*x = lambda*x or
        B*A*x = lambda*x, and A is overwritten by U*A*U**T or L**T*A*L.
        B must have been previously factorized as U**T*U or L*L**T by SPOTRF.

ARGUMENTS

        ITYPE   (input) INTEGER
                = 1: compute inv(U**T)*A*inv(U) or inv(L)*A*inv(L**T);
                = 2 or 3: compute U*A*U**T or L**T*A*L.

        UPLO    (input) CHARACTER*1
                = 'U':  Upper triangle of A is stored and B is factored as
                U**T*U;
                = 'L':  Lower triangle of A is stored and B is factored as
                L*L**T.

        N       (input) INTEGER
                The order of the matrices A and B.  N >= 0.

        A       (input/output) REAL array, dimension (LDA,N)
                On entry, the symmetric matrix A.  If UPLO = 'U', the leading
                N-by-N upper triangular part of A contains the upper
                triangular part of the matrix A, and the strictly lower
                triangular part of A is not referenced.  If UPLO = 'L', the
                leading N-by-N lower triangular part of A contains the lower
                triangular part of the matrix A, and the strictly upper
                triangular part of A is not referenced.
                On exit, if INFO = 0, the transformed matrix, stored in the
                same format as A.

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

        B       (input) REAL array, dimension (LDB,N)
                The triangular factor from the Cholesky factorization of B,
                as returned by SPOTRF.

        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

 LAPACK routine (version 3.3.1)             April 2011                            SSYGST(3lapack)