TESTING/EIG/dsgt01.f(3)    Library Functions Manual    TESTING/EIG/dsgt01.f(3)

NAME
       TESTING/EIG/dsgt01.f

SYNOPSIS
   Functions/Subroutines
       subroutine dsgt01 (itype, uplo, n, m, a, lda, b, ldb, z, ldz, d, work,
           result)
           DSGT01

Function/Subroutine Documentation
   subroutine dsgt01 (integer itype, character uplo, integer n, integer m,
       double precision, dimension( lda, * ) a, integer lda, double precision,
       dimension( ldb, * ) b, integer ldb, double precision, dimension( ldz, *
       ) z, integer ldz, double precision, dimension( * ) d, double precision,
       dimension( * ) work, double precision, dimension( * ) result)
       DSGT01

       Purpose:


            DDGT01 checks a decomposition of the form

               A Z   =  B Z D or
               A B Z =  Z D or
               B A Z =  Z D

            where A is a symmetric matrix, B is
            symmetric positive definite, Z is orthogonal, and D is diagonal.

            One of the following test ratios is computed:

            ITYPE = 1:  RESULT(1) = | A Z - B Z D | / ( |A| |Z| n ulp )

            ITYPE = 2:  RESULT(1) = | A B Z - Z D | / ( |A| |Z| n ulp )

            ITYPE = 3:  RESULT(1) = | B A Z - Z D | / ( |A| |Z| n ulp )

       Parameters
           ITYPE

                     ITYPE is INTEGER
                     The form of the symmetric generalized eigenproblem.
                     = 1:  A*z = (lambda)*B*z
                     = 2:  A*B*z = (lambda)*z
                     = 3:  B*A*z = (lambda)*z

           UPLO

                     UPLO is CHARACTER*1
                     Specifies whether the upper or lower triangular part of the
                     symmetric matrices A and B is stored.
                     = 'U':  Upper triangular
                     = 'L':  Lower triangular

           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           M

                     M is INTEGER
                     The number of eigenvalues found.  0 <= M <= N.

           A

                     A is DOUBLE PRECISION array, dimension (LDA, N)
                     The original symmetric matrix A.

           LDA

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

           B

                     B is DOUBLE PRECISION array, dimension (LDB, N)
                     The original symmetric positive definite matrix B.

           LDB

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

           Z

                     Z is DOUBLE PRECISION array, dimension (LDZ, M)
                     The computed eigenvectors of the generalized eigenproblem.

           LDZ

                     LDZ is INTEGER
                     The leading dimension of the array Z.  LDZ >= max(1,N).

           D

                     D is DOUBLE PRECISION array, dimension (M)
                     The computed eigenvalues of the generalized eigenproblem.

           WORK

                     WORK is DOUBLE PRECISION array, dimension (N*N)

           RESULT

                     RESULT is DOUBLE PRECISION array, dimension (1)
                     The test ratio as described above.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Definition at line 144 of file dsgt01.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0         TESTING/EIG/dsgt01.f(3)