LAPACK: TESTING/EIG/zchkbl.f Source File

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00001       SUBROUTINE ZCHKBL( 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 *  ZCHKBL tests ZGEBAL, a routine for balancing a general complex
00015 *  matrix and isolating some of its eigenvalues.
00016 *
00017 *  Arguments
00018 *  =========
00019 *
00020 *  NIN     (input) INTEGER
00021 *          The logical unit number for input.  NIN > 0.
00022 *
00023 *  NOUT    (input) INTEGER
00024 *          The logical unit number for output.  NOUT > 0.
00025 *
00026 * ======================================================================
00027 *
00028 *     .. Parameters ..
00029       INTEGER            LDA
00030       PARAMETER          ( LDA = 20 )
00031       DOUBLE PRECISION   ZERO
00032       PARAMETER          ( ZERO = 0.0D+0 )
00033 *     ..
00034 *     .. Local Scalars ..
00035       INTEGER            I, IHI, IHIIN, ILO, ILOIN, INFO, J, KNT, N,
00036      $                   NINFO
00037       DOUBLE PRECISION   ANORM, MEPS, RMAX, SFMIN, TEMP, VMAX
00038       COMPLEX*16         CDUM
00039 *     ..
00040 *     .. Local Arrays ..
00041       INTEGER            LMAX( 3 )
00042       DOUBLE PRECISION   DUMMY( 1 ), SCALE( LDA ), SCALIN( LDA )
00043       COMPLEX*16         A( LDA, LDA ), AIN( LDA, LDA )
00044 *     ..
00045 *     .. External Functions ..
00046       DOUBLE PRECISION   DLAMCH, ZLANGE
00047       EXTERNAL           DLAMCH, ZLANGE
00048 *     ..
00049 *     .. External Subroutines ..
00050       EXTERNAL           ZGEBAL
00051 *     ..
00052 *     .. Intrinsic Functions ..
00053       INTRINSIC          ABS, DBLE, DIMAG, MAX
00054 *     ..
00055 *     .. Statement Functions ..
00056       DOUBLE PRECISION   CABS1
00057 *     ..
00058 *     .. Statement Function definitions ..
00059       CABS1( CDUM ) = ABS( DBLE( CDUM ) ) + ABS( DIMAG( CDUM ) )
00060 *     ..
00061 *     .. Executable Statements ..
00062 *
00063       LMAX( 1 ) = 0
00064       LMAX( 2 ) = 0
00065       LMAX( 3 ) = 0
00066       NINFO = 0
00067       KNT = 0
00068       RMAX = ZERO
00069       VMAX = ZERO
00070       SFMIN = DLAMCH( 'S' )
00071       MEPS = DLAMCH( 'E' )
00072 *
00073    10 CONTINUE
00074 *
00075       READ( NIN, FMT = * )N
00076       IF( N.EQ.0 )
00077      $   GO TO 70
00078       DO 20 I = 1, N
00079          READ( NIN, FMT = * )( A( I, J ), J = 1, N )
00080    20 CONTINUE
00081 *
00082       READ( NIN, FMT = * )ILOIN, IHIIN
00083       DO 30 I = 1, N
00084          READ( NIN, FMT = * )( AIN( I, J ), J = 1, N )
00085    30 CONTINUE
00086       READ( NIN, FMT = * )( SCALIN( I ), I = 1, N )
00087 *
00088       ANORM = ZLANGE( 'M', N, N, A, LDA, DUMMY )
00089       KNT = KNT + 1
00090       CALL ZGEBAL( 'B', N, A, LDA, ILO, IHI, SCALE, INFO )
00091 *
00092       IF( INFO.NE.0 ) THEN
00093          NINFO = NINFO + 1
00094          LMAX( 1 ) = KNT
00095       END IF
00096 *
00097       IF( ILO.NE.ILOIN .OR. IHI.NE.IHIIN ) THEN
00098          NINFO = NINFO + 1
00099          LMAX( 2 ) = KNT
00100       END IF
00101 *
00102       DO 50 I = 1, N
00103          DO 40 J = 1, N
00104             TEMP = MAX( CABS1( A( I, J ) ), CABS1( AIN( I, J ) ) )
00105             TEMP = MAX( TEMP, SFMIN )
00106             VMAX = MAX( VMAX, CABS1( A( I, J )-AIN( I, J ) ) / TEMP )
00107    40    CONTINUE
00108    50 CONTINUE
00109 *
00110       DO 60 I = 1, N
00111          TEMP = MAX( SCALE( I ), SCALIN( I ) )
00112          TEMP = MAX( TEMP, SFMIN )
00113          VMAX = MAX( VMAX, ABS( SCALE( I )-SCALIN( I ) ) / TEMP )
00114    60 CONTINUE
00115 *
00116       IF( VMAX.GT.RMAX ) THEN
00117          LMAX( 3 ) = KNT
00118          RMAX = VMAX
00119       END IF
00120 *
00121       GO TO 10
00122 *
00123    70 CONTINUE
00124 *
00125       WRITE( NOUT, FMT = 9999 )
00126  9999 FORMAT( 1X, '.. test output of ZGEBAL .. ' )
00127 *
00128       WRITE( NOUT, FMT = 9998 )RMAX
00129  9998 FORMAT( 1X, 'value of largest test error            = ', D12.3 )
00130       WRITE( NOUT, FMT = 9997 )LMAX( 1 )
00131  9997 FORMAT( 1X, 'example number where info is not zero  = ', I4 )
00132       WRITE( NOUT, FMT = 9996 )LMAX( 2 )
00133  9996 FORMAT( 1X, 'example number where ILO or IHI wrong  = ', I4 )
00134       WRITE( NOUT, FMT = 9995 )LMAX( 3 )
00135  9995 FORMAT( 1X, 'example number having largest error    = ', I4 )
00136       WRITE( NOUT, FMT = 9994 )NINFO
00137  9994 FORMAT( 1X, 'number of examples where info is not 0 = ', I4 )
00138       WRITE( NOUT, FMT = 9993 )KNT
00139  9993 FORMAT( 1X, 'total number of examples tested        = ', I4 )
00140 *
00141       RETURN
00142 *
00143 *     End of ZCHKBL
00144 *
00145       END