LAPACK  3.8.0
LAPACK: Linear Algebra PACKage

◆ zchkbl()

subroutine zchkbl ( integer  NIN,
integer  NOUT 
)

ZCHKBL

Purpose:
 ZCHKBL tests ZGEBAL, a routine for balancing a general complex
 matrix and isolating some of its eigenvalues.
Parameters
[in]NIN
          NIN is INTEGER
          The logical unit number for input.  NIN > 0.
[in]NOUT
          NOUT is INTEGER
          The logical unit number for output.  NOUT > 0.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date
December 2016

Definition at line 56 of file zchkbl.f.

56 *
57 * -- LAPACK test routine (version 3.7.0) --
58 * -- LAPACK is a software package provided by Univ. of Tennessee, --
59 * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
60 * December 2016
61 *
62 * .. Scalar Arguments ..
63  INTEGER nin, nout
64 * ..
65 *
66 * ======================================================================
67 *
68 * .. Parameters ..
69  INTEGER lda
70  parameter( lda = 20 )
71  DOUBLE PRECISION zero
72  parameter( zero = 0.0d+0 )
73 * ..
74 * .. Local Scalars ..
75  INTEGER i, ihi, ihiin, ilo, iloin, info, j, knt, n,
76  $ ninfo
77  DOUBLE PRECISION anorm, meps, rmax, sfmin, temp, vmax
78  COMPLEX*16 cdum
79 * ..
80 * .. Local Arrays ..
81  INTEGER lmax( 3 )
82  DOUBLE PRECISION dummy( 1 ), scale( lda ), scalin( lda )
83  COMPLEX*16 a( lda, lda ), ain( lda, lda )
84 * ..
85 * .. External Functions ..
86  DOUBLE PRECISION dlamch, zlange
87  EXTERNAL dlamch, zlange
88 * ..
89 * .. External Subroutines ..
90  EXTERNAL zgebal
91 * ..
92 * .. Intrinsic Functions ..
93  INTRINSIC abs, dble, dimag, max
94 * ..
95 * .. Statement Functions ..
96  DOUBLE PRECISION cabs1
97 * ..
98 * .. Statement Function definitions ..
99  cabs1( cdum ) = abs( dble( cdum ) ) + abs( dimag( cdum ) )
100 * ..
101 * .. Executable Statements ..
102 *
103  lmax( 1 ) = 0
104  lmax( 2 ) = 0
105  lmax( 3 ) = 0
106  ninfo = 0
107  knt = 0
108  rmax = zero
109  vmax = zero
110  sfmin = dlamch( 'S' )
111  meps = dlamch( 'E' )
112 *
113  10 CONTINUE
114 *
115  READ( nin, fmt = * )n
116  IF( n.EQ.0 )
117  $ GO TO 70
118  DO 20 i = 1, n
119  READ( nin, fmt = * )( a( i, j ), j = 1, n )
120  20 CONTINUE
121 *
122  READ( nin, fmt = * )iloin, ihiin
123  DO 30 i = 1, n
124  READ( nin, fmt = * )( ain( i, j ), j = 1, n )
125  30 CONTINUE
126  READ( nin, fmt = * )( scalin( i ), i = 1, n )
127 *
128  anorm = zlange( 'M', n, n, a, lda, dummy )
129  knt = knt + 1
130  CALL zgebal( 'B', n, a, lda, ilo, ihi, scale, info )
131 *
132  IF( info.NE.0 ) THEN
133  ninfo = ninfo + 1
134  lmax( 1 ) = knt
135  END IF
136 *
137  IF( ilo.NE.iloin .OR. ihi.NE.ihiin ) THEN
138  ninfo = ninfo + 1
139  lmax( 2 ) = knt
140  END IF
141 *
142  DO 50 i = 1, n
143  DO 40 j = 1, n
144  temp = max( cabs1( a( i, j ) ), cabs1( ain( i, j ) ) )
145  temp = max( temp, sfmin )
146  vmax = max( vmax, cabs1( a( i, j )-ain( i, j ) ) / temp )
147  40 CONTINUE
148  50 CONTINUE
149 *
150  DO 60 i = 1, n
151  temp = max( scale( i ), scalin( i ) )
152  temp = max( temp, sfmin )
153  vmax = max( vmax, abs( scale( i )-scalin( i ) ) / temp )
154  60 CONTINUE
155 *
156  IF( vmax.GT.rmax ) THEN
157  lmax( 3 ) = knt
158  rmax = vmax
159  END IF
160 *
161  GO TO 10
162 *
163  70 CONTINUE
164 *
165  WRITE( nout, fmt = 9999 )
166  9999 FORMAT( 1x, '.. test output of ZGEBAL .. ' )
167 *
168  WRITE( nout, fmt = 9998 )rmax
169  9998 FORMAT( 1x, 'value of largest test error = ', d12.3 )
170  WRITE( nout, fmt = 9997 )lmax( 1 )
171  9997 FORMAT( 1x, 'example number where info is not zero = ', i4 )
172  WRITE( nout, fmt = 9996 )lmax( 2 )
173  9996 FORMAT( 1x, 'example number where ILO or IHI wrong = ', i4 )
174  WRITE( nout, fmt = 9995 )lmax( 3 )
175  9995 FORMAT( 1x, 'example number having largest error = ', i4 )
176  WRITE( nout, fmt = 9994 )ninfo
177  9994 FORMAT( 1x, 'number of examples where info is not 0 = ', i4 )
178  WRITE( nout, fmt = 9993 )knt
179  9993 FORMAT( 1x, 'total number of examples tested = ', i4 )
180 *
181  RETURN
182 *
183 * End of ZCHKBL
184 *
double precision function dlamch(CMACH)
DLAMCH
Definition: dlamch.f:65
double precision function zlange(NORM, M, N, A, LDA, WORK)
ZLANGE returns the value of the 1-norm, Frobenius norm, infinity-norm, or the largest absolute value ...
Definition: zlange.f:117
subroutine zgebal(JOB, N, A, LDA, ILO, IHI, SCALE, INFO)
ZGEBAL
Definition: zgebal.f:164
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