LAPACK  3.4.1
LAPACK: Linear Algebra PACKage
dchkbl.f
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00001 *> \brief \b DCHKBL
00002 *
00003 *  =========== DOCUMENTATION ===========
00004 *
00005 * Online html documentation available at 
00006 *            http://www.netlib.org/lapack/explore-html/ 
00007 *
00008 *  Definition:
00009 *  ===========
00010 *
00011 *       SUBROUTINE DCHKBL( NIN, NOUT )
00012 * 
00013 *       .. Scalar Arguments ..
00014 *       INTEGER            NIN, NOUT
00015 *       ..
00016 *  
00017 *
00018 *> \par Purpose:
00019 *  =============
00020 *>
00021 *> \verbatim
00022 *>
00023 *> DCHKBL tests DGEBAL, a routine for balancing a general real
00024 *> matrix and isolating some of its eigenvalues.
00025 *> \endverbatim
00026 *
00027 *  Arguments:
00028 *  ==========
00029 *
00030 *> \param[in] NIN
00031 *> \verbatim
00032 *>          NIN is INTEGER
00033 *>          The logical unit number for input.  NIN > 0.
00034 *> \endverbatim
00035 *>
00036 *> \param[in] NOUT
00037 *> \verbatim
00038 *>          NOUT is INTEGER
00039 *>          The logical unit number for output.  NOUT > 0.
00040 *> \endverbatim
00041 *
00042 *  Authors:
00043 *  ========
00044 *
00045 *> \author Univ. of Tennessee 
00046 *> \author Univ. of California Berkeley 
00047 *> \author Univ. of Colorado Denver 
00048 *> \author NAG Ltd. 
00049 *
00050 *> \date November 2011
00051 *
00052 *> \ingroup double_eig
00053 *
00054 *  =====================================================================
00055       SUBROUTINE DCHKBL( NIN, NOUT )
00056 *
00057 *  -- LAPACK test routine (version 3.4.0) --
00058 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
00059 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
00060 *     November 2011
00061 *
00062 *     .. Scalar Arguments ..
00063       INTEGER            NIN, NOUT
00064 *     ..
00065 *
00066 * ======================================================================
00067 *
00068 *     .. Parameters ..
00069       INTEGER            LDA
00070       PARAMETER          ( LDA = 20 )
00071       DOUBLE PRECISION   ZERO
00072       PARAMETER          ( ZERO = 0.0D+0 )
00073 *     ..
00074 *     .. Local Scalars ..
00075       INTEGER            I, IHI, IHIIN, ILO, ILOIN, INFO, J, KNT, N,
00076      $                   NINFO
00077       DOUBLE PRECISION   ANORM, MEPS, RMAX, SFMIN, TEMP, VMAX
00078 *     ..
00079 *     .. Local Arrays ..
00080       INTEGER            LMAX( 3 )
00081       DOUBLE PRECISION   A( LDA, LDA ), AIN( LDA, LDA ), DUMMY( 1 ),
00082      $                   SCALE( LDA ), SCALIN( LDA )
00083 *     ..
00084 *     .. External Functions ..
00085       DOUBLE PRECISION   DLAMCH, DLANGE
00086       EXTERNAL           DLAMCH, DLANGE
00087 *     ..
00088 *     .. External Subroutines ..
00089       EXTERNAL           DGEBAL
00090 *     ..
00091 *     .. Intrinsic Functions ..
00092       INTRINSIC          ABS, MAX
00093 *     ..
00094 *     .. Executable Statements ..
00095 *
00096       LMAX( 1 ) = 0
00097       LMAX( 2 ) = 0
00098       LMAX( 3 ) = 0
00099       NINFO = 0
00100       KNT = 0
00101       RMAX = ZERO
00102       VMAX = ZERO
00103       SFMIN = DLAMCH( 'S' )
00104       MEPS = DLAMCH( 'E' )
00105 *
00106    10 CONTINUE
00107 *
00108       READ( NIN, FMT = * )N
00109       IF( N.EQ.0 )
00110      $   GO TO 70
00111       DO 20 I = 1, N
00112          READ( NIN, FMT = * )( A( I, J ), J = 1, N )
00113    20 CONTINUE
00114 *
00115       READ( NIN, FMT = * )ILOIN, IHIIN
00116       DO 30 I = 1, N
00117          READ( NIN, FMT = * )( AIN( I, J ), J = 1, N )
00118    30 CONTINUE
00119       READ( NIN, FMT = * )( SCALIN( I ), I = 1, N )
00120 *
00121       ANORM = DLANGE( 'M', N, N, A, LDA, DUMMY )
00122       KNT = KNT + 1
00123 *
00124       CALL DGEBAL( 'B', N, A, LDA, ILO, IHI, SCALE, INFO )
00125 *
00126       IF( INFO.NE.0 ) THEN
00127          NINFO = NINFO + 1
00128          LMAX( 1 ) = KNT
00129       END IF
00130 *
00131       IF( ILO.NE.ILOIN .OR. IHI.NE.IHIIN ) THEN
00132          NINFO = NINFO + 1
00133          LMAX( 2 ) = KNT
00134       END IF
00135 *
00136       DO 50 I = 1, N
00137          DO 40 J = 1, N
00138             TEMP = MAX( A( I, J ), AIN( I, J ) )
00139             TEMP = MAX( TEMP, SFMIN )
00140             VMAX = MAX( VMAX, ABS( A( I, J )-AIN( I, J ) ) / TEMP )
00141    40    CONTINUE
00142    50 CONTINUE
00143 *
00144       DO 60 I = 1, N
00145          TEMP = MAX( SCALE( I ), SCALIN( I ) )
00146          TEMP = MAX( TEMP, SFMIN )
00147          VMAX = MAX( VMAX, ABS( SCALE( I )-SCALIN( I ) ) / TEMP )
00148    60 CONTINUE
00149 *
00150 *
00151       IF( VMAX.GT.RMAX ) THEN
00152          LMAX( 3 ) = KNT
00153          RMAX = VMAX
00154       END IF
00155 *
00156       GO TO 10
00157 *
00158    70 CONTINUE
00159 *
00160       WRITE( NOUT, FMT = 9999 )
00161  9999 FORMAT( 1X, '.. test output of DGEBAL .. ' )
00162 *
00163       WRITE( NOUT, FMT = 9998 )RMAX
00164  9998 FORMAT( 1X, 'value of largest test error            = ', D12.3 )
00165       WRITE( NOUT, FMT = 9997 )LMAX( 1 )
00166  9997 FORMAT( 1X, 'example number where info is not zero  = ', I4 )
00167       WRITE( NOUT, FMT = 9996 )LMAX( 2 )
00168  9996 FORMAT( 1X, 'example number where ILO or IHI wrong  = ', I4 )
00169       WRITE( NOUT, FMT = 9995 )LMAX( 3 )
00170  9995 FORMAT( 1X, 'example number having largest error    = ', I4 )
00171       WRITE( NOUT, FMT = 9994 )NINFO
00172  9994 FORMAT( 1X, 'number of examples where info is not 0 = ', I4 )
00173       WRITE( NOUT, FMT = 9993 )KNT
00174  9993 FORMAT( 1X, 'total number of examples tested        = ', I4 )
00175 *
00176       RETURN
00177 *
00178 *     End of DCHKBL
00179 *
00180       END
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