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

NAME

       LAPACK-3  -  reduces  a real symmetric-definite generalized eigenproblem to standard form,
       using packed storage

SYNOPSIS

       SUBROUTINE DSPGST( ITYPE, UPLO, N, AP, BP, INFO )

           CHARACTER      UPLO

           INTEGER        INFO, ITYPE, N

           DOUBLE         PRECISION AP( * ), BP( * )

PURPOSE

       DSPGST reduces a real symmetric-definite generalized eigenproblem to standard form,  using
       packed storage.
        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 DPPTRF.

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.

        AP      (input/output) DOUBLE PRECISION array, dimension (N*(N+1)/2)
                On entry, the upper or lower triangle of the symmetric matrix
                A, packed columnwise in a linear array.  The j-th column of A
                is stored in the array AP as follows:
                if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
                if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
                On exit, if INFO = 0, the transformed matrix, stored in the
                same format as A.

        BP      (input) DOUBLE PRECISION array, dimension (N*(N+1)/2)
                The triangular factor from the Cholesky factorization of B,
                stored in the same format as A, as returned by DPPTRF.

        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                            DSPGST(3lapack)