1*> \brief \b CCHKBL
2*
3*  =========== DOCUMENTATION ===========
4*
5* Online html documentation available at
6*            http://www.netlib.org/lapack/explore-html/
7*
8*  Definition:
9*  ===========
10*
11*       SUBROUTINE CCHKBL( NIN, NOUT )
12*
13*       .. Scalar Arguments ..
14*       INTEGER            NIN, NOUT
15*       ..
16*
17*
18*> \par Purpose:
19*  =============
20*>
21*> \verbatim
22*>
23*> CCHKBL tests CGEBAL, a routine for balancing a general complex
24*> matrix and isolating some of its eigenvalues.
25*> \endverbatim
26*
27*  Arguments:
28*  ==========
29*
30*> \param[in] NIN
31*> \verbatim
32*>          NIN is INTEGER
33*>          The logical unit number for input.  NIN > 0.
34*> \endverbatim
35*>
36*> \param[in] NOUT
37*> \verbatim
38*>          NOUT is INTEGER
39*>          The logical unit number for output.  NOUT > 0.
40*> \endverbatim
41*
42*  Authors:
43*  ========
44*
45*> \author Univ. of Tennessee
46*> \author Univ. of California Berkeley
47*> \author Univ. of Colorado Denver
48*> \author NAG Ltd.
49*
50*> \ingroup complex_eig
51*
52*  =====================================================================
53      SUBROUTINE CCHKBL( NIN, NOUT )
54*
55*  -- LAPACK test routine --
56*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
57*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
58*
59*     .. Scalar Arguments ..
60      INTEGER            NIN, NOUT
61*     ..
62*
63* ======================================================================
64*
65*     .. Parameters ..
66      INTEGER            LDA
67      PARAMETER          ( LDA = 20 )
68      REAL               ZERO
69      PARAMETER          ( ZERO = 0.0E+0 )
70*     ..
71*     .. Local Scalars ..
72      INTEGER            I, IHI, IHIIN, ILO, ILOIN, INFO, J, KNT, N,
73     $                   NINFO
74      REAL               ANORM, MEPS, RMAX, SFMIN, TEMP, VMAX
75      COMPLEX            CDUM
76*     ..
77*     .. Local Arrays ..
78      INTEGER            LMAX( 3 )
79      REAL               DUMMY( 1 ), SCALE( LDA ), SCALIN( LDA )
80      COMPLEX            A( LDA, LDA ), AIN( LDA, LDA )
81*     ..
82*     .. External Functions ..
83      REAL               CLANGE, SLAMCH
84      EXTERNAL           CLANGE, SLAMCH
85*     ..
86*     .. External Subroutines ..
87      EXTERNAL           CGEBAL
88*     ..
89*     .. Intrinsic Functions ..
90      INTRINSIC          ABS, AIMAG, MAX, REAL
91*     ..
92*     .. Statement Functions ..
93      REAL               CABS1
94*     ..
95*     .. Statement Function definitions ..
96      CABS1( CDUM ) = ABS( REAL( CDUM ) ) + ABS( AIMAG( CDUM ) )
97*     ..
98*     .. Executable Statements ..
99*
100      LMAX( 1 ) = 0
101      LMAX( 2 ) = 0
102      LMAX( 3 ) = 0
103      NINFO = 0
104      KNT = 0
105      RMAX = ZERO
106      VMAX = ZERO
107      SFMIN = SLAMCH( 'S' )
108      MEPS = SLAMCH( 'E' )
109*
110   10 CONTINUE
111*
112      READ( NIN, FMT = * )N
113      IF( N.EQ.0 )
114     $   GO TO 70
115      DO 20 I = 1, N
116         READ( NIN, FMT = * )( A( I, J ), J = 1, N )
117   20 CONTINUE
118*
119      READ( NIN, FMT = * )ILOIN, IHIIN
120      DO 30 I = 1, N
121         READ( NIN, FMT = * )( AIN( I, J ), J = 1, N )
122   30 CONTINUE
123      READ( NIN, FMT = * )( SCALIN( I ), I = 1, N )
124*
125      ANORM = CLANGE( 'M', N, N, A, LDA, DUMMY )
126      KNT = KNT + 1
127      CALL CGEBAL( 'B', N, A, LDA, ILO, IHI, SCALE, INFO )
128*
129      IF( INFO.NE.0 ) THEN
130         NINFO = NINFO + 1
131         LMAX( 1 ) = KNT
132      END IF
133*
134      IF( ILO.NE.ILOIN .OR. IHI.NE.IHIIN ) THEN
135         NINFO = NINFO + 1
136         LMAX( 2 ) = KNT
137      END IF
138*
139      DO 50 I = 1, N
140         DO 40 J = 1, N
141            TEMP = MAX( CABS1( A( I, J ) ), CABS1( AIN( I, J ) ) )
142            TEMP = MAX( TEMP, SFMIN )
143            VMAX = MAX( VMAX, CABS1( A( I, J )-AIN( I, J ) ) / TEMP )
144   40    CONTINUE
145   50 CONTINUE
146*
147      DO 60 I = 1, N
148         TEMP = MAX( SCALE( I ), SCALIN( I ) )
149         TEMP = MAX( TEMP, SFMIN )
150         VMAX = MAX( VMAX, ABS( SCALE( I )-SCALIN( I ) ) / TEMP )
151   60 CONTINUE
152*
153      IF( VMAX.GT.RMAX ) THEN
154         LMAX( 3 ) = KNT
155         RMAX = VMAX
156      END IF
157*
158      GO TO 10
159*
160   70 CONTINUE
161*
162      WRITE( NOUT, FMT = 9999 )
163 9999 FORMAT( 1X, '.. test output of CGEBAL .. ' )
164*
165      WRITE( NOUT, FMT = 9998 )RMAX
166 9998 FORMAT( 1X, 'value of largest test error            = ', E12.3 )
167      WRITE( NOUT, FMT = 9997 )LMAX( 1 )
168 9997 FORMAT( 1X, 'example number where info is not zero  = ', I4 )
169      WRITE( NOUT, FMT = 9996 )LMAX( 2 )
170 9996 FORMAT( 1X, 'example number where ILO or IHI wrong  = ', I4 )
171      WRITE( NOUT, FMT = 9995 )LMAX( 3 )
172 9995 FORMAT( 1X, 'example number having largest error    = ', I4 )
173      WRITE( NOUT, FMT = 9994 )NINFO
174 9994 FORMAT( 1X, 'number of examples where info is not 0 = ', I4 )
175      WRITE( NOUT, FMT = 9993 )KNT
176 9993 FORMAT( 1X, 'total number of examples tested        = ', I4 )
177*
178      RETURN
179*
180*     End of CCHKBL
181*
182      END
183