LAPACK: TESTING/EIG/zchkgl.f Source File

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00001       SUBROUTINE ZCHKGL( NIN, NOUT )
00002 *
00003 *  -- LAPACK test routine (version 3.1) --
00004 *     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
00005 *     November 2006
00006 *
00007 *     .. Scalar Arguments ..
00008       INTEGER            NIN, NOUT
00009 *     ..
00010 *
00011 *  Purpose
00012 *  =======
00013 *
00014 *  ZCHKGL tests ZGGBAL, a routine for balancing a matrix pair (A, B).
00015 *
00016 *  Arguments
00017 *  =========
00018 *
00019 *  NIN     (input) INTEGER
00020 *          The logical unit number for input.  NIN > 0.
00021 *
00022 *  NOUT    (input) INTEGER
00023 *          The logical unit number for output.  NOUT > 0.
00024 *
00025 *  =====================================================================
00026 *
00027 *     .. Parameters ..
00028       INTEGER            LDA, LDB, LWORK
00029       PARAMETER          ( LDA = 20, LDB = 20, LWORK = 6*LDA )
00030       DOUBLE PRECISION   ZERO
00031       PARAMETER          ( ZERO = 0.0D+0 )
00032 *     ..
00033 *     .. Local Scalars ..
00034       INTEGER            I, IHI, IHIIN, ILO, ILOIN, INFO, J, KNT, N,
00035      $                   NINFO
00036       DOUBLE PRECISION   ANORM, BNORM, EPS, RMAX, VMAX
00037 *     ..
00038 *     .. Local Arrays ..
00039       INTEGER            LMAX( 3 )
00040       DOUBLE PRECISION   LSCALE( LDA ), LSCLIN( LDA ), RSCALE( LDA ),
00041      $                   RSCLIN( LDA ), WORK( LWORK )
00042       COMPLEX*16         A( LDA, LDA ), AIN( LDA, LDA ), B( LDB, LDB ),
00043      $                   BIN( LDB, LDB )
00044 *     ..
00045 *     .. External Functions ..
00046       DOUBLE PRECISION   DLAMCH, ZLANGE
00047       EXTERNAL           DLAMCH, ZLANGE
00048 *     ..
00049 *     .. External Subroutines ..
00050       EXTERNAL           ZGGBAL
00051 *     ..
00052 *     .. Intrinsic Functions ..
00053       INTRINSIC          ABS, MAX
00054 *     ..
00055 *     .. Executable Statements ..
00056 *
00057       LMAX( 1 ) = 0
00058       LMAX( 2 ) = 0
00059       LMAX( 3 ) = 0
00060       NINFO = 0
00061       KNT = 0
00062       RMAX = ZERO
00063 *
00064       EPS = DLAMCH( 'Precision' )
00065 *
00066    10 CONTINUE
00067 *
00068       READ( NIN, FMT = * )N
00069       IF( N.EQ.0 )
00070      $   GO TO 90
00071       DO 20 I = 1, N
00072          READ( NIN, FMT = * )( A( I, J ), J = 1, N )
00073    20 CONTINUE
00074 *
00075       DO 30 I = 1, N
00076          READ( NIN, FMT = * )( B( I, J ), J = 1, N )
00077    30 CONTINUE
00078 *
00079       READ( NIN, FMT = * )ILOIN, IHIIN
00080       DO 40 I = 1, N
00081          READ( NIN, FMT = * )( AIN( I, J ), J = 1, N )
00082    40 CONTINUE
00083       DO 50 I = 1, N
00084          READ( NIN, FMT = * )( BIN( I, J ), J = 1, N )
00085    50 CONTINUE
00086 *
00087       READ( NIN, FMT = * )( LSCLIN( I ), I = 1, N )
00088       READ( NIN, FMT = * )( RSCLIN( I ), I = 1, N )
00089 *
00090       ANORM = ZLANGE( 'M', N, N, A, LDA, WORK )
00091       BNORM = ZLANGE( 'M', N, N, B, LDB, WORK )
00092 *
00093       KNT = KNT + 1
00094 *
00095       CALL ZGGBAL( 'B', N, A, LDA, B, LDB, ILO, IHI, LSCALE, RSCALE,
00096      $             WORK, INFO )
00097 *
00098       IF( INFO.NE.0 ) THEN
00099          NINFO = NINFO + 1
00100          LMAX( 1 ) = KNT
00101       END IF
00102 *
00103       IF( ILO.NE.ILOIN .OR. IHI.NE.IHIIN ) THEN
00104          NINFO = NINFO + 1
00105          LMAX( 2 ) = KNT
00106       END IF
00107 *
00108       VMAX = ZERO
00109       DO 70 I = 1, N
00110          DO 60 J = 1, N
00111             VMAX = MAX( VMAX, ABS( A( I, J )-AIN( I, J ) ) )
00112             VMAX = MAX( VMAX, ABS( B( I, J )-BIN( I, J ) ) )
00113    60    CONTINUE
00114    70 CONTINUE
00115 *
00116       DO 80 I = 1, N
00117          VMAX = MAX( VMAX, ABS( LSCALE( I )-LSCLIN( I ) ) )
00118          VMAX = MAX( VMAX, ABS( RSCALE( I )-RSCLIN( I ) ) )
00119    80 CONTINUE
00120 *
00121       VMAX = VMAX / ( EPS*MAX( ANORM, BNORM ) )
00122 *
00123       IF( VMAX.GT.RMAX ) THEN
00124          LMAX( 3 ) = KNT
00125          RMAX = VMAX
00126       END IF
00127 *
00128       GO TO 10
00129 *
00130    90 CONTINUE
00131 *
00132       WRITE( NOUT, FMT = 9999 )
00133  9999 FORMAT( ' .. test output of ZGGBAL .. ' )
00134 *
00135       WRITE( NOUT, FMT = 9998 )RMAX
00136  9998 FORMAT( ' ratio of largest test error              = ', D12.3 )
00137       WRITE( NOUT, FMT = 9997 )LMAX( 1 )
00138  9997 FORMAT( ' example number where info is not zero    = ', I4 )
00139       WRITE( NOUT, FMT = 9996 )LMAX( 2 )
00140  9996 FORMAT( ' example number where ILO or IHI is wrong = ', I4 )
00141       WRITE( NOUT, FMT = 9995 )LMAX( 3 )
00142  9995 FORMAT( ' example number having largest error      = ', I4 )
00143       WRITE( NOUT, FMT = 9994 )NINFO
00144  9994 FORMAT( ' number of examples where info is not 0   = ', I4 )
00145       WRITE( NOUT, FMT = 9993 )KNT
00146  9993 FORMAT( ' total number of examples tested          = ', I4 )
00147 *
00148       RETURN
00149 *
00150 *     End of ZCHKGL
00151 *
00152       END