*> \brief \b CGET22 * * =========== DOCUMENTATION =========== * * Online html documentation available at * http://www.netlib.org/lapack/explore-html/ * * Definition: * =========== * * SUBROUTINE CGET22( TRANSA, TRANSE, TRANSW, N, A, LDA, E, LDE, W, * WORK, RWORK, RESULT ) * * .. Scalar Arguments .. * CHARACTER TRANSA, TRANSE, TRANSW * INTEGER LDA, LDE, N * .. * .. Array Arguments .. * REAL RESULT( 2 ), RWORK( * ) * COMPLEX A( LDA, * ), E( LDE, * ), W( * ), WORK( * ) * .. * * *> \par Purpose: * ============= *> *> \verbatim *> *> CGET22 does an eigenvector check. *> *> The basic test is: *> *> RESULT(1) = | A E - E W | / ( |A| |E| ulp ) *> *> using the 1-norm. It also tests the normalization of E: *> *> RESULT(2) = max | m-norm(E(j)) - 1 | / ( n ulp ) *> j *> *> where E(j) is the j-th eigenvector, and m-norm is the max-norm of a *> vector. The max-norm of a complex n-vector x in this case is the *> maximum of |re(x(i)| + |im(x(i)| over i = 1, ..., n. *> \endverbatim * * Arguments: * ========== * *> \param[in] TRANSA *> \verbatim *> TRANSA is CHARACTER*1 *> Specifies whether or not A is transposed. *> = 'N': No transpose *> = 'T': Transpose *> = 'C': Conjugate transpose *> \endverbatim *> *> \param[in] TRANSE *> \verbatim *> TRANSE is CHARACTER*1 *> Specifies whether or not E is transposed. *> = 'N': No transpose, eigenvectors are in columns of E *> = 'T': Transpose, eigenvectors are in rows of E *> = 'C': Conjugate transpose, eigenvectors are in rows of E *> \endverbatim *> *> \param[in] TRANSW *> \verbatim *> TRANSW is CHARACTER*1 *> Specifies whether or not W is transposed. *> = 'N': No transpose *> = 'T': Transpose, same as TRANSW = 'N' *> = 'C': Conjugate transpose, use -WI(j) instead of WI(j) *> \endverbatim *> *> \param[in] N *> \verbatim *> N is INTEGER *> The order of the matrix A. N >= 0. *> \endverbatim *> *> \param[in] A *> \verbatim *> A is COMPLEX array, dimension (LDA,N) *> The matrix whose eigenvectors are in E. *> \endverbatim *> *> \param[in] LDA *> \verbatim *> LDA is INTEGER *> The leading dimension of the array A. LDA >= max(1,N). *> \endverbatim *> *> \param[in] E *> \verbatim *> E is COMPLEX array, dimension (LDE,N) *> The matrix of eigenvectors. If TRANSE = 'N', the eigenvectors *> are stored in the columns of E, if TRANSE = 'T' or 'C', the *> eigenvectors are stored in the rows of E. *> \endverbatim *> *> \param[in] LDE *> \verbatim *> LDE is INTEGER *> The leading dimension of the array E. LDE >= max(1,N). *> \endverbatim *> *> \param[in] W *> \verbatim *> W is COMPLEX array, dimension (N) *> The eigenvalues of A. *> \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 (2) *> RESULT(1) = | A E - E W | / ( |A| |E| ulp ) *> RESULT(2) = max | m-norm(E(j)) - 1 | / ( n ulp ) *> \endverbatim * * Authors: * ======== * *> \author Univ. of Tennessee *> \author Univ. of California Berkeley *> \author Univ. of Colorado Denver *> \author NAG Ltd. * *> \ingroup complex_eig * * ===================================================================== SUBROUTINE CGET22( TRANSA, TRANSE, TRANSW, N, A, LDA, E, LDE, W, $ 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 TRANSA, TRANSE, TRANSW INTEGER LDA, LDE, N * .. * .. Array Arguments .. REAL RESULT( 2 ), RWORK( * ) COMPLEX A( LDA, * ), E( LDE, * ), W( * ), WORK( * ) * .. * * ===================================================================== * * .. 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 .. CHARACTER NORMA, NORME INTEGER ITRNSE, ITRNSW, J, JCOL, JOFF, JROW, JVEC REAL ANORM, ENORM, ENRMAX, ENRMIN, ERRNRM, TEMP1, $ ULP, UNFL COMPLEX WTEMP * .. * .. External Functions .. LOGICAL LSAME REAL CLANGE, SLAMCH EXTERNAL LSAME, CLANGE, SLAMCH * .. * .. External Subroutines .. EXTERNAL CGEMM, CLASET * .. * .. Intrinsic Functions .. INTRINSIC ABS, AIMAG, CONJG, MAX, MIN, REAL * .. * .. Executable Statements .. * * Initialize RESULT (in case N=0) * RESULT( 1 ) = ZERO RESULT( 2 ) = ZERO IF( N.LE.0 ) $ RETURN * UNFL = SLAMCH( 'Safe minimum' ) ULP = SLAMCH( 'Precision' ) * ITRNSE = 0 ITRNSW = 0 NORMA = 'O' NORME = 'O' * IF( LSAME( TRANSA, 'T' ) .OR. LSAME( TRANSA, 'C' ) ) THEN NORMA = 'I' END IF * IF( LSAME( TRANSE, 'T' ) ) THEN ITRNSE = 1 NORME = 'I' ELSE IF( LSAME( TRANSE, 'C' ) ) THEN ITRNSE = 2 NORME = 'I' END IF * IF( LSAME( TRANSW, 'C' ) ) THEN ITRNSW = 1 END IF * * Normalization of E: * ENRMIN = ONE / ULP ENRMAX = ZERO IF( ITRNSE.EQ.0 ) THEN DO 20 JVEC = 1, N TEMP1 = ZERO DO 10 J = 1, N TEMP1 = MAX( TEMP1, ABS( REAL( E( J, JVEC ) ) )+ $ ABS( AIMAG( E( J, JVEC ) ) ) ) 10 CONTINUE ENRMIN = MIN( ENRMIN, TEMP1 ) ENRMAX = MAX( ENRMAX, TEMP1 ) 20 CONTINUE ELSE DO 30 JVEC = 1, N RWORK( JVEC ) = ZERO 30 CONTINUE * DO 50 J = 1, N DO 40 JVEC = 1, N RWORK( JVEC ) = MAX( RWORK( JVEC ), $ ABS( REAL( E( JVEC, J ) ) )+ $ ABS( AIMAG( E( JVEC, J ) ) ) ) 40 CONTINUE 50 CONTINUE * DO 60 JVEC = 1, N ENRMIN = MIN( ENRMIN, RWORK( JVEC ) ) ENRMAX = MAX( ENRMAX, RWORK( JVEC ) ) 60 CONTINUE END IF * * Norm of A: * ANORM = MAX( CLANGE( NORMA, N, N, A, LDA, RWORK ), UNFL ) * * Norm of E: * ENORM = MAX( CLANGE( NORME, N, N, E, LDE, RWORK ), ULP ) * * Norm of error: * * Error = AE - EW * CALL CLASET( 'Full', N, N, CZERO, CZERO, WORK, N ) * JOFF = 0 DO 100 JCOL = 1, N IF( ITRNSW.EQ.0 ) THEN WTEMP = W( JCOL ) ELSE WTEMP = CONJG( W( JCOL ) ) END IF * IF( ITRNSE.EQ.0 ) THEN DO 70 JROW = 1, N WORK( JOFF+JROW ) = E( JROW, JCOL )*WTEMP 70 CONTINUE ELSE IF( ITRNSE.EQ.1 ) THEN DO 80 JROW = 1, N WORK( JOFF+JROW ) = E( JCOL, JROW )*WTEMP 80 CONTINUE ELSE DO 90 JROW = 1, N WORK( JOFF+JROW ) = CONJG( E( JCOL, JROW ) )*WTEMP 90 CONTINUE END IF JOFF = JOFF + N 100 CONTINUE * CALL CGEMM( TRANSA, TRANSE, N, N, N, CONE, A, LDA, E, LDE, -CONE, $ WORK, N ) * ERRNRM = CLANGE( 'One', N, N, WORK, N, RWORK ) / ENORM * * Compute RESULT(1) (avoiding under/overflow) * IF( ANORM.GT.ERRNRM ) THEN RESULT( 1 ) = ( ERRNRM / ANORM ) / ULP ELSE IF( ANORM.LT.ONE ) THEN RESULT( 1 ) = ( MIN( ERRNRM, ANORM ) / ANORM ) / ULP ELSE RESULT( 1 ) = MIN( ERRNRM / ANORM, ONE ) / ULP END IF END IF * * Compute RESULT(2) : the normalization error in E. * RESULT( 2 ) = MAX( ABS( ENRMAX-ONE ), ABS( ENRMIN-ONE ) ) / $ ( REAL( N )*ULP ) * RETURN * * End of CGET22 * END