LAPACK 3.3.1 Linear Algebra PACKage

# dchkgl.f

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```00001       SUBROUTINE DCHKGL( 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 *  DCHKGL tests DGGBAL, 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( 5 )
00040       DOUBLE PRECISION   A( LDA, LDA ), AIN( LDA, LDA ), B( LDB, LDB ),
00041      \$                   BIN( LDB, LDB ), LSCALE( LDA ), LSCLIN( LDA ),
00042      \$                   RSCALE( LDA ), RSCLIN( LDA ), WORK( LWORK )
00043 *     ..
00044 *     .. External Functions ..
00045       DOUBLE PRECISION   DLAMCH, DLANGE
00046       EXTERNAL           DLAMCH, DLANGE
00047 *     ..
00048 *     .. External Subroutines ..
00049       EXTERNAL           DGGBAL
00050 *     ..
00051 *     .. Intrinsic Functions ..
00052       INTRINSIC          ABS, MAX
00053 *     ..
00054 *     .. Executable Statements ..
00055 *
00056       LMAX( 1 ) = 0
00057       LMAX( 2 ) = 0
00058       LMAX( 3 ) = 0
00059       NINFO = 0
00060       KNT = 0
00061       RMAX = ZERO
00062 *
00063       EPS = DLAMCH( 'Precision' )
00064 *
00065    10 CONTINUE
00066 *
00067       READ( NIN, FMT = * )N
00068       IF( N.EQ.0 )
00069      \$   GO TO 90
00070       DO 20 I = 1, N
00071          READ( NIN, FMT = * )( A( I, J ), J = 1, N )
00072    20 CONTINUE
00073 *
00074       DO 30 I = 1, N
00075          READ( NIN, FMT = * )( B( I, J ), J = 1, N )
00076    30 CONTINUE
00077 *
00078       READ( NIN, FMT = * )ILOIN, IHIIN
00079       DO 40 I = 1, N
00080          READ( NIN, FMT = * )( AIN( I, J ), J = 1, N )
00081    40 CONTINUE
00082       DO 50 I = 1, N
00083          READ( NIN, FMT = * )( BIN( I, J ), J = 1, N )
00084    50 CONTINUE
00085 *
00086       READ( NIN, FMT = * )( LSCLIN( I ), I = 1, N )
00087       READ( NIN, FMT = * )( RSCLIN( I ), I = 1, N )
00088 *
00089       ANORM = DLANGE( 'M', N, N, A, LDA, WORK )
00090       BNORM = DLANGE( 'M', N, N, B, LDB, WORK )
00091 *
00092       KNT = KNT + 1
00093 *
00094       CALL DGGBAL( 'B', N, A, LDA, B, LDB, ILO, IHI, LSCALE, RSCALE,
00095      \$             WORK, INFO )
00096 *
00097       IF( INFO.NE.0 ) THEN
00098          NINFO = NINFO + 1
00099          LMAX( 1 ) = KNT
00100       END IF
00101 *
00102       IF( ILO.NE.ILOIN .OR. IHI.NE.IHIIN ) THEN
00103          NINFO = NINFO + 1
00104          LMAX( 2 ) = KNT
00105       END IF
00106 *
00107       VMAX = ZERO
00108       DO 70 I = 1, N
00109          DO 60 J = 1, N
00110             VMAX = MAX( VMAX, ABS( A( I, J )-AIN( I, J ) ) )
00111             VMAX = MAX( VMAX, ABS( B( I, J )-BIN( I, J ) ) )
00112    60    CONTINUE
00113    70 CONTINUE
00114 *
00115       DO 80 I = 1, N
00116          VMAX = MAX( VMAX, ABS( LSCALE( I )-LSCLIN( I ) ) )
00117          VMAX = MAX( VMAX, ABS( RSCALE( I )-RSCLIN( I ) ) )
00118    80 CONTINUE
00119 *
00120       VMAX = VMAX / ( EPS*MAX( ANORM, BNORM ) )
00121 *
00122       IF( VMAX.GT.RMAX ) THEN
00123          LMAX( 3 ) = KNT
00124          RMAX = VMAX
00125       END IF
00126 *
00127       GO TO 10
00128 *
00129    90 CONTINUE
00130 *
00131       WRITE( NOUT, FMT = 9999 )
00132  9999 FORMAT( 1X, '.. test output of DGGBAL .. ' )
00133 *
00134       WRITE( NOUT, FMT = 9998 )RMAX
00135  9998 FORMAT( 1X, 'value of largest test error            = ', D12.3 )
00136       WRITE( NOUT, FMT = 9997 )LMAX( 1 )
00137  9997 FORMAT( 1X, 'example number where info is not zero  = ', I4 )
00138       WRITE( NOUT, FMT = 9996 )LMAX( 2 )
00139  9996 FORMAT( 1X, 'example number where ILO or IHI wrong  = ', I4 )
00140       WRITE( NOUT, FMT = 9995 )LMAX( 3 )
00141  9995 FORMAT( 1X, 'example number having largest error    = ', I4 )
00142       WRITE( NOUT, FMT = 9994 )NINFO
00143  9994 FORMAT( 1X, 'number of examples where info is not 0 = ', I4 )
00144       WRITE( NOUT, FMT = 9993 )KNT
00145  9993 FORMAT( 1X, 'total number of examples tested        = ', I4 )
00146 *
00147       RETURN
00148 *
00149 *     End of DCHKGL
00150 *
00151       END
```