Cloned library LAPACK-3.11.0 with extra build files for internal package management.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

253 lines
6.6 KiB

2 years ago
*> \brief \b CSGT01
*
* =========== DOCUMENTATION ===========
*
* Online html documentation available at
* http://www.netlib.org/lapack/explore-html/
*
* Definition:
* ===========
*
* SUBROUTINE CSGT01( ITYPE, UPLO, N, M, A, LDA, B, LDB, Z, LDZ, D,
* WORK, RWORK, RESULT )
*
* .. Scalar Arguments ..
* CHARACTER UPLO
* INTEGER ITYPE, LDA, LDB, LDZ, M, N
* ..
* .. Array Arguments ..
* REAL D( * ), RESULT( * ), RWORK( * )
* COMPLEX A( LDA, * ), B( LDB, * ), WORK( * ),
* $ Z( LDZ, * )
* ..
*
*
*> \par Purpose:
* =============
*>
*> \verbatim
*>
*> CSGT01 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 Hermitian matrix, B is Hermitian positive definite,
*> Z is unitary, 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 )
*> \endverbatim
*
* Arguments:
* ==========
*
*> \param[in] ITYPE
*> \verbatim
*> ITYPE is INTEGER
*> The form of the Hermitian generalized eigenproblem.
*> = 1: A*z = (lambda)*B*z
*> = 2: A*B*z = (lambda)*z
*> = 3: B*A*z = (lambda)*z
*> \endverbatim
*>
*> \param[in] UPLO
*> \verbatim
*> UPLO is CHARACTER*1
*> Specifies whether the upper or lower triangular part of the
*> Hermitian matrices A and B is stored.
*> = 'U': Upper triangular
*> = 'L': Lower triangular
*> \endverbatim
*>
*> \param[in] N
*> \verbatim
*> N is INTEGER
*> The order of the matrix A. N >= 0.
*> \endverbatim
*>
*> \param[in] M
*> \verbatim
*> M is INTEGER
*> The number of eigenvalues found. M >= 0.
*> \endverbatim
*>
*> \param[in] A
*> \verbatim
*> A is COMPLEX array, dimension (LDA, N)
*> The original Hermitian matrix A.
*> \endverbatim
*>
*> \param[in] LDA
*> \verbatim
*> LDA is INTEGER
*> The leading dimension of the array A. LDA >= max(1,N).
*> \endverbatim
*>
*> \param[in] B
*> \verbatim
*> B is COMPLEX array, dimension (LDB, N)
*> The original Hermitian positive definite matrix B.
*> \endverbatim
*>
*> \param[in] LDB
*> \verbatim
*> LDB is INTEGER
*> The leading dimension of the array B. LDB >= max(1,N).
*> \endverbatim
*>
*> \param[in] Z
*> \verbatim
*> Z is COMPLEX array, dimension (LDZ, M)
*> The computed eigenvectors of the generalized eigenproblem.
*> \endverbatim
*>
*> \param[in] LDZ
*> \verbatim
*> LDZ is INTEGER
*> The leading dimension of the array Z. LDZ >= max(1,N).
*> \endverbatim
*>
*> \param[in] D
*> \verbatim
*> D is REAL array, dimension (M)
*> The computed eigenvalues of the generalized eigenproblem.
*> \endverbatim
*>
*> \param[out] WORK
*> \verbatim
*> WORK is COMPLEX array, dimension (N*N)
*> \endverbatim
*>
*> \param[out] RWORK
*> \verbatim
*> RWORK is REAL array, dimension (N)
*> \endverbatim
*>
*> \param[out] RESULT
*> \verbatim
*> RESULT is REAL array, dimension (1)
*> The test ratio as described above.
*> \endverbatim
*
* Authors:
* ========
*
*> \author Univ. of Tennessee
*> \author Univ. of California Berkeley
*> \author Univ. of Colorado Denver
*> \author NAG Ltd.
*
*> \ingroup complex_eig
*
* =====================================================================
SUBROUTINE CSGT01( ITYPE, UPLO, N, M, A, LDA, B, LDB, Z, LDZ, D,
$ WORK, RWORK, RESULT )
*
* -- LAPACK test routine --
* -- LAPACK is a software package provided by Univ. of Tennessee, --
* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
*
* .. Scalar Arguments ..
CHARACTER UPLO
INTEGER ITYPE, LDA, LDB, LDZ, M, N
* ..
* .. Array Arguments ..
REAL D( * ), RESULT( * ), RWORK( * )
COMPLEX A( LDA, * ), B( LDB, * ), WORK( * ),
$ Z( LDZ, * )
* ..
*
* =====================================================================
*
* .. Parameters ..
REAL ZERO, ONE
PARAMETER ( ZERO = 0.0E+0, ONE = 1.0E+0 )
COMPLEX CZERO, CONE
PARAMETER ( CZERO = ( 0.0E+0, 0.0E+0 ),
$ CONE = ( 1.0E+0, 0.0E+0 ) )
* ..
* .. Local Scalars ..
INTEGER I
REAL ANORM, ULP
* ..
* .. External Functions ..
REAL CLANGE, CLANHE, SLAMCH
EXTERNAL CLANGE, CLANHE, SLAMCH
* ..
* .. External Subroutines ..
EXTERNAL CHEMM, CSSCAL
* ..
* .. Executable Statements ..
*
RESULT( 1 ) = ZERO
IF( N.LE.0 )
$ RETURN
*
ULP = SLAMCH( 'Epsilon' )
*
* Compute product of 1-norms of A and Z.
*
ANORM = CLANHE( '1', UPLO, N, A, LDA, RWORK )*
$ CLANGE( '1', N, M, Z, LDZ, RWORK )
IF( ANORM.EQ.ZERO )
$ ANORM = ONE
*
IF( ITYPE.EQ.1 ) THEN
*
* Norm of AZ - BZD
*
CALL CHEMM( 'Left', UPLO, N, M, CONE, A, LDA, Z, LDZ, CZERO,
$ WORK, N )
DO 10 I = 1, M
CALL CSSCAL( N, D( I ), Z( 1, I ), 1 )
10 CONTINUE
CALL CHEMM( 'Left', UPLO, N, M, CONE, B, LDB, Z, LDZ, -CONE,
$ WORK, N )
*
RESULT( 1 ) = ( CLANGE( '1', N, M, WORK, N, RWORK ) / ANORM ) /
$ ( N*ULP )
*
ELSE IF( ITYPE.EQ.2 ) THEN
*
* Norm of ABZ - ZD
*
CALL CHEMM( 'Left', UPLO, N, M, CONE, B, LDB, Z, LDZ, CZERO,
$ WORK, N )
DO 20 I = 1, M
CALL CSSCAL( N, D( I ), Z( 1, I ), 1 )
20 CONTINUE
CALL CHEMM( 'Left', UPLO, N, M, CONE, A, LDA, WORK, N, -CONE,
$ Z, LDZ )
*
RESULT( 1 ) = ( CLANGE( '1', N, M, Z, LDZ, RWORK ) / ANORM ) /
$ ( N*ULP )
*
ELSE IF( ITYPE.EQ.3 ) THEN
*
* Norm of BAZ - ZD
*
CALL CHEMM( 'Left', UPLO, N, M, CONE, A, LDA, Z, LDZ, CZERO,
$ WORK, N )
DO 30 I = 1, M
CALL CSSCAL( N, D( I ), Z( 1, I ), 1 )
30 CONTINUE
CALL CHEMM( 'Left', UPLO, N, M, CONE, B, LDB, WORK, N, -CONE,
$ Z, LDZ )
*
RESULT( 1 ) = ( CLANGE( '1', N, M, Z, LDZ, RWORK ) / ANORM ) /
$ ( N*ULP )
END IF
*
RETURN
*
* End of CSGT01
*
END