SUBROUTINE ZCHKGK( NIN, NOUT ) * * -- LAPACK test routine (version 3.1) -- * Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. * November 2006 * * .. Scalar Arguments .. INTEGER NIN, NOUT * .. * * Purpose * ======= * * ZCHKGK tests ZGGBAK, a routine for backward balancing of * a matrix pair (A, B). * * Arguments * ========= * * NIN (input) INTEGER * The logical unit number for input. NIN > 0. * * NOUT (input) INTEGER * The logical unit number for output. NOUT > 0. * * ===================================================================== * * .. Parameters .. INTEGER LDA, LDB, LDVL, LDVR PARAMETER ( LDA = 50, LDB = 50, LDVL = 50, LDVR = 50 ) INTEGER LDE, LDF, LDWORK, LRWORK PARAMETER ( LDE = 50, LDF = 50, LDWORK = 50, $ LRWORK = 6*50 ) DOUBLE PRECISION ZERO PARAMETER ( ZERO = 0.0D+0 ) COMPLEX*16 CZERO, CONE PARAMETER ( CZERO = ( 0.0D+0, 0.0D+0 ), $ CONE = ( 1.0D+0, 0.0D+0 ) ) * .. * .. Local Scalars .. INTEGER I, IHI, ILO, INFO, J, KNT, M, N, NINFO DOUBLE PRECISION ANORM, BNORM, EPS, RMAX, VMAX COMPLEX*16 CDUM * .. * .. Local Arrays .. INTEGER LMAX( 4 ) DOUBLE PRECISION LSCALE( LDA ), RSCALE( LDA ), RWORK( LRWORK ) COMPLEX*16 A( LDA, LDA ), AF( LDA, LDA ), B( LDB, LDB ), $ BF( LDB, LDB ), E( LDE, LDE ), F( LDF, LDF ), $ VL( LDVL, LDVL ), VLF( LDVL, LDVL ), $ VR( LDVR, LDVR ), VRF( LDVR, LDVR ), $ WORK( LDWORK, LDWORK ) * .. * .. External Functions .. DOUBLE PRECISION DLAMCH, ZLANGE EXTERNAL DLAMCH, ZLANGE * .. * .. External Subroutines .. EXTERNAL ZGEMM, ZGGBAK, ZGGBAL, ZLACPY * .. * .. Intrinsic Functions .. INTRINSIC ABS, DBLE, DIMAG, MAX * .. * .. Statement Functions .. DOUBLE PRECISION CABS1 * .. * .. Statement Function definitions .. CABS1( CDUM ) = ABS( DBLE( CDUM ) ) + ABS( DIMAG( CDUM ) ) * .. * .. Executable Statements .. * LMAX( 1 ) = 0 LMAX( 2 ) = 0 LMAX( 3 ) = 0 LMAX( 4 ) = 0 NINFO = 0 KNT = 0 RMAX = ZERO * EPS = DLAMCH( 'Precision' ) * 10 CONTINUE READ( NIN, FMT = * )N, M IF( N.EQ.0 ) $ GO TO 100 * DO 20 I = 1, N READ( NIN, FMT = * )( A( I, J ), J = 1, N ) 20 CONTINUE * DO 30 I = 1, N READ( NIN, FMT = * )( B( I, J ), J = 1, N ) 30 CONTINUE * DO 40 I = 1, N READ( NIN, FMT = * )( VL( I, J ), J = 1, M ) 40 CONTINUE * DO 50 I = 1, N READ( NIN, FMT = * )( VR( I, J ), J = 1, M ) 50 CONTINUE * KNT = KNT + 1 * ANORM = ZLANGE( 'M', N, N, A, LDA, RWORK ) BNORM = ZLANGE( 'M', N, N, B, LDB, RWORK ) * CALL ZLACPY( 'FULL', N, N, A, LDA, AF, LDA ) CALL ZLACPY( 'FULL', N, N, B, LDB, BF, LDB ) * CALL ZGGBAL( 'B', N, A, LDA, B, LDB, ILO, IHI, LSCALE, RSCALE, $ RWORK, INFO ) IF( INFO.NE.0 ) THEN NINFO = NINFO + 1 LMAX( 1 ) = KNT END IF * CALL ZLACPY( 'FULL', N, M, VL, LDVL, VLF, LDVL ) CALL ZLACPY( 'FULL', N, M, VR, LDVR, VRF, LDVR ) * CALL ZGGBAK( 'B', 'L', N, ILO, IHI, LSCALE, RSCALE, M, VL, LDVL, $ INFO ) IF( INFO.NE.0 ) THEN NINFO = NINFO + 1 LMAX( 2 ) = KNT END IF * CALL ZGGBAK( 'B', 'R', N, ILO, IHI, LSCALE, RSCALE, M, VR, LDVR, $ INFO ) IF( INFO.NE.0 ) THEN NINFO = NINFO + 1 LMAX( 3 ) = KNT END IF * * Test of ZGGBAK * * Check tilde(VL)'*A*tilde(VR) - VL'*tilde(A)*VR * where tilde(A) denotes the transformed matrix. * CALL ZGEMM( 'N', 'N', N, M, N, CONE, AF, LDA, VR, LDVR, CZERO, $ WORK, LDWORK ) CALL ZGEMM( 'C', 'N', M, M, N, CONE, VL, LDVL, WORK, LDWORK, $ CZERO, E, LDE ) * CALL ZGEMM( 'N', 'N', N, M, N, CONE, A, LDA, VRF, LDVR, CZERO, $ WORK, LDWORK ) CALL ZGEMM( 'C', 'N', M, M, N, CONE, VLF, LDVL, WORK, LDWORK, $ CZERO, F, LDF ) * VMAX = ZERO DO 70 J = 1, M DO 60 I = 1, M VMAX = MAX( VMAX, CABS1( E( I, J )-F( I, J ) ) ) 60 CONTINUE 70 CONTINUE VMAX = VMAX / ( EPS*MAX( ANORM, BNORM ) ) IF( VMAX.GT.RMAX ) THEN LMAX( 4 ) = KNT RMAX = VMAX END IF * * Check tilde(VL)'*B*tilde(VR) - VL'*tilde(B)*VR * CALL ZGEMM( 'N', 'N', N, M, N, CONE, BF, LDB, VR, LDVR, CZERO, $ WORK, LDWORK ) CALL ZGEMM( 'C', 'N', M, M, N, CONE, VL, LDVL, WORK, LDWORK, $ CZERO, E, LDE ) * CALL ZGEMM( 'n', 'n', N, M, N, CONE, B, LDB, VRF, LDVR, CZERO, $ WORK, LDWORK ) CALL ZGEMM( 'C', 'N', M, M, N, CONE, VLF, LDVL, WORK, LDWORK, $ CZERO, F, LDF ) * VMAX = ZERO DO 90 J = 1, M DO 80 I = 1, M VMAX = MAX( VMAX, CABS1( E( I, J )-F( I, J ) ) ) 80 CONTINUE 90 CONTINUE VMAX = VMAX / ( EPS*MAX( ANORM, BNORM ) ) IF( VMAX.GT.RMAX ) THEN LMAX( 4 ) = KNT RMAX = VMAX END IF * GO TO 10 * 100 CONTINUE * WRITE( NOUT, FMT = 9999 ) 9999 FORMAT( 1X, '.. test output of ZGGBAK .. ' ) * WRITE( NOUT, FMT = 9998 )RMAX 9998 FORMAT( ' value of largest test error =', D12.3 ) WRITE( NOUT, FMT = 9997 )LMAX( 1 ) 9997 FORMAT( ' example number where ZGGBAL info is not 0 =', I4 ) WRITE( NOUT, FMT = 9996 )LMAX( 2 ) 9996 FORMAT( ' example number where ZGGBAK(L) info is not 0 =', I4 ) WRITE( NOUT, FMT = 9995 )LMAX( 3 ) 9995 FORMAT( ' example number where ZGGBAK(R) info is not 0 =', I4 ) WRITE( NOUT, FMT = 9994 )LMAX( 4 ) 9994 FORMAT( ' example number having largest error =', I4 ) WRITE( NOUT, FMT = 9992 )NINFO 9992 FORMAT( ' number of examples where info is not 0 =', I4 ) WRITE( NOUT, FMT = 9991 )KNT 9991 FORMAT( ' total number of examples tested =', I4 ) * RETURN * * End of ZCHKGK * END