1*> \brief \b ZEBCHVXX
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 ZEBCHVXX( THRESH, PATH )
12*
13*     .. Scalar Arguments ..
14*      DOUBLE PRECISION  THRESH
15*      CHARACTER*3       PATH
16*       ..
17*
18*  Purpose
19*  ======
20*
21*> \details \b Purpose:
22*> \verbatim
23*>
24*>  ZEBCHVXX will run Z**SVXX on a series of Hilbert matrices and then
25*>  compare the error bounds returned by Z**SVXX to see if the returned
26*>  answer indeed falls within those bounds.
27*>
28*>  Eight test ratios will be computed.  The tests will pass if they are .LT.
29*>  THRESH.  There are two cases that are determined by 1 / (SQRT( N ) * EPS).
30*>  If that value is .LE. to the component wise reciprocal condition number,
31*>  it uses the guaranteed case, other wise it uses the unguaranteed case.
32*>
33*>  Test ratios:
34*>     Let Xc be X_computed and Xt be X_truth.
35*>     The norm used is the infinity norm.
36*>
37*>     Let A be the guaranteed case and B be the unguaranteed case.
38*>
39*>       1. Normwise guaranteed forward error bound.
40*>       A: norm ( abs( Xc - Xt ) / norm ( Xt ) .LE. ERRBND( *, nwise_i, bnd_i ) and
41*>          ERRBND( *, nwise_i, bnd_i ) .LE. MAX(SQRT(N),10) * EPS.
42*>          If these conditions are met, the test ratio is set to be
43*>          ERRBND( *, nwise_i, bnd_i ) / MAX(SQRT(N), 10).  Otherwise it is 1/EPS.
44*>       B: For this case, CGESVXX should just return 1.  If it is less than
45*>          one, treat it the same as in 1A.  Otherwise it fails. (Set test
46*>          ratio to ERRBND( *, nwise_i, bnd_i ) * THRESH?)
47*>
48*>       2. Componentwise guaranteed forward error bound.
49*>       A: norm ( abs( Xc(j) - Xt(j) ) ) / norm (Xt(j)) .LE. ERRBND( *, cwise_i, bnd_i )
50*>          for all j .AND. ERRBND( *, cwise_i, bnd_i ) .LE. MAX(SQRT(N), 10) * EPS.
51*>          If these conditions are met, the test ratio is set to be
52*>          ERRBND( *, cwise_i, bnd_i ) / MAX(SQRT(N), 10).  Otherwise it is 1/EPS.
53*>       B: Same as normwise test ratio.
54*>
55*>       3. Backwards error.
56*>       A: The test ratio is set to BERR/EPS.
57*>       B: Same test ratio.
58*>
59*>       4. Reciprocal condition number.
60*>       A: A condition number is computed with Xt and compared with the one
61*>          returned from CGESVXX.  Let RCONDc be the RCOND returned by CGESVXX
62*>          and RCONDt be the RCOND from the truth value.  Test ratio is set to
63*>          MAX(RCONDc/RCONDt, RCONDt/RCONDc).
64*>       B: Test ratio is set to 1 / (EPS * RCONDc).
65*>
66*>       5. Reciprocal normwise condition number.
67*>       A: The test ratio is set to
68*>          MAX(ERRBND( *, nwise_i, cond_i ) / NCOND, NCOND / ERRBND( *, nwise_i, cond_i )).
69*>       B: Test ratio is set to 1 / (EPS * ERRBND( *, nwise_i, cond_i )).
70*>
71*>       6. Reciprocal componentwise condition number.
72*>       A: Test ratio is set to
73*>          MAX(ERRBND( *, cwise_i, cond_i ) / CCOND, CCOND / ERRBND( *, cwise_i, cond_i )).
74*>       B: Test ratio is set to 1 / (EPS * ERRBND( *, cwise_i, cond_i )).
75*>
76*>     .. Parameters ..
77*>     NMAX is determined by the largest number in the inverse of the hilbert
78*>     matrix.  Precision is exhausted when the largest entry in it is greater
79*>     than 2 to the power of the number of bits in the fraction of the data
80*>     type used plus one, which is 24 for single precision.
81*>     NMAX should be 6 for single and 11 for double.
82*> \endverbatim
83*
84*  Authors:
85*  ========
86*
87*> \author Univ. of Tennessee
88*> \author Univ. of California Berkeley
89*> \author Univ. of Colorado Denver
90*> \author NAG Ltd.
91*
92*> \ingroup complex16_lin
93*
94*  =====================================================================
95      SUBROUTINE ZEBCHVXX( THRESH, PATH )
96      IMPLICIT NONE
97*     .. Scalar Arguments ..
98      DOUBLE PRECISION  THRESH
99      CHARACTER*3       PATH
100
101      INTEGER            NMAX, NPARAMS, NERRBND, NTESTS, KL, KU
102      PARAMETER          (NMAX = 10, NPARAMS = 2, NERRBND = 3,
103     $                    NTESTS = 6)
104
105*     .. Local Scalars ..
106      INTEGER            N, NRHS, INFO, I ,J, k, NFAIL, LDA,
107     $                   N_AUX_TESTS, LDAB, LDAFB
108      CHARACTER          FACT, TRANS, UPLO, EQUED
109      CHARACTER*2        C2
110      CHARACTER(3)       NGUAR, CGUAR
111      LOGICAL            printed_guide
112      DOUBLE PRECISION   NCOND, CCOND, M, NORMDIF, NORMT, RCOND,
113     $                   RNORM, RINORM, SUMR, SUMRI, EPS,
114     $                   BERR(NMAX), RPVGRW, ORCOND,
115     $                   CWISE_ERR, NWISE_ERR, CWISE_BND, NWISE_BND,
116     $                   CWISE_RCOND, NWISE_RCOND,
117     $                   CONDTHRESH, ERRTHRESH
118      COMPLEX*16         ZDUM
119
120*     .. Local Arrays ..
121      DOUBLE PRECISION   TSTRAT(NTESTS), RINV(NMAX), PARAMS(NPARAMS),
122     $                   S(NMAX),R(NMAX),C(NMAX),RWORK(3*NMAX),
123     $                   DIFF(NMAX, NMAX),
124     $                   ERRBND_N(NMAX*3), ERRBND_C(NMAX*3)
125      INTEGER            IPIV(NMAX)
126      COMPLEX*16         A(NMAX,NMAX),INVHILB(NMAX,NMAX),X(NMAX,NMAX),
127     $                   WORK(NMAX*3*5), AF(NMAX, NMAX),B(NMAX, NMAX),
128     $                   ACOPY(NMAX, NMAX),
129     $                   AB( (NMAX-1)+(NMAX-1)+1, NMAX ),
130     $                   ABCOPY( (NMAX-1)+(NMAX-1)+1, NMAX ),
131     $                   AFB( 2*(NMAX-1)+(NMAX-1)+1, NMAX )
132
133*     .. External Functions ..
134      DOUBLE PRECISION   DLAMCH
135
136*     .. External Subroutines ..
137      EXTERNAL           ZLAHILB, ZGESVXX, ZPOSVXX, ZSYSVXX,
138     $                   ZGBSVXX, ZLACPY, LSAMEN
139      LOGICAL            LSAMEN
140
141*     .. Intrinsic Functions ..
142      INTRINSIC          SQRT, MAX, ABS, DBLE, DIMAG
143
144*     .. Statement Functions ..
145      DOUBLE PRECISION   CABS1
146
147*     .. Statement Function Definitions ..
148      CABS1( ZDUM ) = ABS( DBLE( ZDUM ) ) + ABS( DIMAG( ZDUM ) )
149
150*     .. Parameters ..
151      INTEGER            NWISE_I, CWISE_I
152      PARAMETER          (NWISE_I = 1, CWISE_I = 1)
153      INTEGER            BND_I, COND_I
154      PARAMETER          (BND_I = 2, COND_I = 3)
155
156*  Create the loop to test out the Hilbert matrices
157
158      FACT = 'E'
159      UPLO = 'U'
160      TRANS = 'N'
161      EQUED = 'N'
162      EPS = DLAMCH('Epsilon')
163      NFAIL = 0
164      N_AUX_TESTS = 0
165      LDA = NMAX
166      LDAB = (NMAX-1)+(NMAX-1)+1
167      LDAFB = 2*(NMAX-1)+(NMAX-1)+1
168      C2 = PATH( 2: 3 )
169
170*     Main loop to test the different Hilbert Matrices.
171
172      printed_guide = .false.
173
174      DO N = 1 , NMAX
175         PARAMS(1) = -1
176         PARAMS(2) = -1
177
178         KL = N-1
179         KU = N-1
180         NRHS = n
181         M = MAX(SQRT(DBLE(N)), 10.0D+0)
182
183*        Generate the Hilbert matrix, its inverse, and the
184*        right hand side, all scaled by the LCM(1,..,2N-1).
185         CALL ZLAHILB(N, N, A, LDA, INVHILB, LDA, B,
186     $        LDA, WORK, INFO, PATH)
187
188*        Copy A into ACOPY.
189         CALL ZLACPY('ALL', N, N, A, NMAX, ACOPY, NMAX)
190
191*        Store A in band format for GB tests
192         DO J = 1, N
193            DO I = 1, KL+KU+1
194               AB( I, J ) = (0.0D+0,0.0D+0)
195            END DO
196         END DO
197         DO J = 1, N
198            DO I = MAX( 1, J-KU ), MIN( N, J+KL )
199               AB( KU+1+I-J, J ) = A( I, J )
200            END DO
201         END DO
202
203*        Copy AB into ABCOPY.
204         DO J = 1, N
205            DO I = 1, KL+KU+1
206               ABCOPY( I, J ) = (0.0D+0,0.0D+0)
207            END DO
208         END DO
209         CALL ZLACPY('ALL', KL+KU+1, N, AB, LDAB, ABCOPY, LDAB)
210
211*        Call Z**SVXX with default PARAMS and N_ERR_BND = 3.
212         IF ( LSAMEN( 2, C2, 'SY' ) ) THEN
213            CALL ZSYSVXX(FACT, UPLO, N, NRHS, ACOPY, LDA, AF, LDA,
214     $           IPIV, EQUED, S, B, LDA, X, LDA, ORCOND,
215     $           RPVGRW, BERR, NERRBND, ERRBND_N, ERRBND_C, NPARAMS,
216     $           PARAMS, WORK, RWORK, INFO)
217         ELSE IF ( LSAMEN( 2, C2, 'PO' ) ) THEN
218            CALL ZPOSVXX(FACT, UPLO, N, NRHS, ACOPY, LDA, AF, LDA,
219     $           EQUED, S, B, LDA, X, LDA, ORCOND,
220     $           RPVGRW, BERR, NERRBND, ERRBND_N, ERRBND_C, NPARAMS,
221     $           PARAMS, WORK, RWORK, INFO)
222         ELSE IF ( LSAMEN( 2, C2, 'HE' ) ) THEN
223            CALL ZHESVXX(FACT, UPLO, N, NRHS, ACOPY, LDA, AF, LDA,
224     $           IPIV, EQUED, S, B, LDA, X, LDA, ORCOND,
225     $           RPVGRW, BERR, NERRBND, ERRBND_N, ERRBND_C, NPARAMS,
226     $           PARAMS, WORK, RWORK, INFO)
227         ELSE IF ( LSAMEN( 2, C2, 'GB' ) ) THEN
228            CALL ZGBSVXX(FACT, TRANS, N, KL, KU, NRHS, ABCOPY,
229     $           LDAB, AFB, LDAFB, IPIV, EQUED, R, C, B,
230     $           LDA, X, LDA, ORCOND, RPVGRW, BERR, NERRBND,
231     $           ERRBND_N, ERRBND_C, NPARAMS, PARAMS, WORK, RWORK,
232     $           INFO)
233         ELSE
234            CALL ZGESVXX(FACT, TRANS, N, NRHS, ACOPY, LDA, AF, LDA,
235     $           IPIV, EQUED, R, C, B, LDA, X, LDA, ORCOND,
236     $           RPVGRW, BERR, NERRBND, ERRBND_N, ERRBND_C, NPARAMS,
237     $           PARAMS, WORK, RWORK, INFO)
238         END IF
239
240         N_AUX_TESTS = N_AUX_TESTS + 1
241         IF (ORCOND .LT. EPS) THEN
242!        Either factorization failed or the matrix is flagged, and 1 <=
243!        INFO <= N+1. We don't decide based on rcond anymore.
244!            IF (INFO .EQ. 0 .OR. INFO .GT. N+1) THEN
245!               NFAIL = NFAIL + 1
246!               WRITE (*, FMT=8000) N, INFO, ORCOND, RCOND
247!            END IF
248         ELSE
249!        Either everything succeeded (INFO == 0) or some solution failed
250!        to converge (INFO > N+1).
251            IF (INFO .GT. 0 .AND. INFO .LE. N+1) THEN
252               NFAIL = NFAIL + 1
253               WRITE (*, FMT=8000) C2, N, INFO, ORCOND, RCOND
254            END IF
255         END IF
256
257*        Calculating the difference between Z**SVXX's X and the true X.
258         DO I = 1,N
259            DO J =1,NRHS
260               DIFF(I,J) = X(I,J) - INVHILB(I,J)
261            END DO
262         END DO
263
264*        Calculating the RCOND
265         RNORM = 0
266         RINORM = 0
267         IF ( LSAMEN( 2, C2, 'PO' ) .OR. LSAMEN( 2, C2, 'SY' ) .OR.
268     $        LSAMEN( 2, C2, 'HE' ) ) THEN
269            DO I = 1, N
270               SUMR = 0
271               SUMRI = 0
272               DO J = 1, N
273                  SUMR = SUMR + S(I) * CABS1(A(I,J)) * S(J)
274                  SUMRI = SUMRI + CABS1(INVHILB(I, J)) / (S(J) * S(I))
275               END DO
276               RNORM = MAX(RNORM,SUMR)
277               RINORM = MAX(RINORM,SUMRI)
278            END DO
279         ELSE IF ( LSAMEN( 2, C2, 'GE' ) .OR. LSAMEN( 2, C2, 'GB' ) )
280     $           THEN
281            DO I = 1, N
282               SUMR = 0
283               SUMRI = 0
284               DO J = 1, N
285                  SUMR = SUMR + R(I) * CABS1(A(I,J)) * C(J)
286                  SUMRI = SUMRI + CABS1(INVHILB(I, J)) / (R(J) * C(I))
287               END DO
288               RNORM = MAX(RNORM,SUMR)
289               RINORM = MAX(RINORM,SUMRI)
290            END DO
291         END IF
292
293         RNORM = RNORM / CABS1(A(1, 1))
294         RCOND = 1.0D+0/(RNORM * RINORM)
295
296*        Calculating the R for normwise rcond.
297         DO I = 1, N
298            RINV(I) = 0.0D+0
299         END DO
300         DO J = 1, N
301            DO I = 1, N
302               RINV(I) = RINV(I) + CABS1(A(I,J))
303            END DO
304         END DO
305
306*        Calculating the Normwise rcond.
307         RINORM = 0.0D+0
308         DO I = 1, N
309            SUMRI = 0.0D+0
310            DO J = 1, N
311               SUMRI = SUMRI + CABS1(INVHILB(I,J) * RINV(J))
312            END DO
313            RINORM = MAX(RINORM, SUMRI)
314         END DO
315
316!        invhilb is the inverse *unscaled* Hilbert matrix, so scale its norm
317!        by 1/A(1,1) to make the scaling match A (the scaled Hilbert matrix)
318         NCOND = CABS1(A(1,1)) / RINORM
319
320         CONDTHRESH = M * EPS
321         ERRTHRESH = M * EPS
322
323         DO K = 1, NRHS
324            NORMT = 0.0D+0
325            NORMDIF = 0.0D+0
326            CWISE_ERR = 0.0D+0
327            DO I = 1, N
328               NORMT = MAX(CABS1(INVHILB(I, K)), NORMT)
329               NORMDIF = MAX(CABS1(X(I,K) - INVHILB(I,K)), NORMDIF)
330               IF (INVHILB(I,K) .NE. 0.0D+0) THEN
331                  CWISE_ERR = MAX(CABS1(X(I,K) - INVHILB(I,K))
332     $                            /CABS1(INVHILB(I,K)), CWISE_ERR)
333               ELSE IF (X(I, K) .NE. 0.0D+0) THEN
334                  CWISE_ERR = DLAMCH('OVERFLOW')
335               END IF
336            END DO
337            IF (NORMT .NE. 0.0D+0) THEN
338               NWISE_ERR = NORMDIF / NORMT
339            ELSE IF (NORMDIF .NE. 0.0D+0) THEN
340               NWISE_ERR = DLAMCH('OVERFLOW')
341            ELSE
342               NWISE_ERR = 0.0D+0
343            ENDIF
344
345            DO I = 1, N
346               RINV(I) = 0.0D+0
347            END DO
348            DO J = 1, N
349               DO I = 1, N
350                  RINV(I) = RINV(I) + CABS1(A(I, J) * INVHILB(J, K))
351               END DO
352            END DO
353            RINORM = 0.0D+0
354            DO I = 1, N
355               SUMRI = 0.0D+0
356               DO J = 1, N
357                  SUMRI = SUMRI
358     $                 + CABS1(INVHILB(I, J) * RINV(J) / INVHILB(I, K))
359               END DO
360               RINORM = MAX(RINORM, SUMRI)
361            END DO
362!        invhilb is the inverse *unscaled* Hilbert matrix, so scale its norm
363!        by 1/A(1,1) to make the scaling match A (the scaled Hilbert matrix)
364            CCOND = CABS1(A(1,1))/RINORM
365
366!        Forward error bound tests
367            NWISE_BND = ERRBND_N(K + (BND_I-1)*NRHS)
368            CWISE_BND = ERRBND_C(K + (BND_I-1)*NRHS)
369            NWISE_RCOND = ERRBND_N(K + (COND_I-1)*NRHS)
370            CWISE_RCOND = ERRBND_C(K + (COND_I-1)*NRHS)
371!            write (*,*) 'nwise : ', n, k, ncond, nwise_rcond,
372!     $           condthresh, ncond.ge.condthresh
373!            write (*,*) 'nwise2: ', k, nwise_bnd, nwise_err, errthresh
374            IF (NCOND .GE. CONDTHRESH) THEN
375               NGUAR = 'YES'
376               IF (NWISE_BND .GT. ERRTHRESH) THEN
377                  TSTRAT(1) = 1/(2.0D+0*EPS)
378               ELSE
379                  IF (NWISE_BND .NE. 0.0D+0) THEN
380                     TSTRAT(1) = NWISE_ERR / NWISE_BND
381                  ELSE IF (NWISE_ERR .NE. 0.0D+0) THEN
382                     TSTRAT(1) = 1/(16.0*EPS)
383                  ELSE
384                     TSTRAT(1) = 0.0D+0
385                  END IF
386                  IF (TSTRAT(1) .GT. 1.0D+0) THEN
387                     TSTRAT(1) = 1/(4.0D+0*EPS)
388                  END IF
389               END IF
390            ELSE
391               NGUAR = 'NO'
392               IF (NWISE_BND .LT. 1.0D+0) THEN
393                  TSTRAT(1) = 1/(8.0D+0*EPS)
394               ELSE
395                  TSTRAT(1) = 1.0D+0
396               END IF
397            END IF
398!            write (*,*) 'cwise : ', n, k, ccond, cwise_rcond,
399!     $           condthresh, ccond.ge.condthresh
400!            write (*,*) 'cwise2: ', k, cwise_bnd, cwise_err, errthresh
401            IF (CCOND .GE. CONDTHRESH) THEN
402               CGUAR = 'YES'
403               IF (CWISE_BND .GT. ERRTHRESH) THEN
404                  TSTRAT(2) = 1/(2.0D+0*EPS)
405               ELSE
406                  IF (CWISE_BND .NE. 0.0D+0) THEN
407                     TSTRAT(2) = CWISE_ERR / CWISE_BND
408                  ELSE IF (CWISE_ERR .NE. 0.0D+0) THEN
409                     TSTRAT(2) = 1/(16.0D+0*EPS)
410                  ELSE
411                     TSTRAT(2) = 0.0D+0
412                  END IF
413                  IF (TSTRAT(2) .GT. 1.0D+0) TSTRAT(2) = 1/(4.0D+0*EPS)
414               END IF
415            ELSE
416               CGUAR = 'NO'
417               IF (CWISE_BND .LT. 1.0D+0) THEN
418                  TSTRAT(2) = 1/(8.0D+0*EPS)
419               ELSE
420                  TSTRAT(2) = 1.0D+0
421               END IF
422            END IF
423
424!     Backwards error test
425            TSTRAT(3) = BERR(K)/EPS
426
427!     Condition number tests
428            TSTRAT(4) = RCOND / ORCOND
429            IF (RCOND .GE. CONDTHRESH .AND. TSTRAT(4) .LT. 1.0D+0)
430     $         TSTRAT(4) = 1.0D+0 / TSTRAT(4)
431
432            TSTRAT(5) = NCOND / NWISE_RCOND
433            IF (NCOND .GE. CONDTHRESH .AND. TSTRAT(5) .LT. 1.0D+0)
434     $         TSTRAT(5) = 1.0D+0 / TSTRAT(5)
435
436            TSTRAT(6) = CCOND / NWISE_RCOND
437            IF (CCOND .GE. CONDTHRESH .AND. TSTRAT(6) .LT. 1.0D+0)
438     $         TSTRAT(6) = 1.0D+0 / TSTRAT(6)
439
440            DO I = 1, NTESTS
441               IF (TSTRAT(I) .GT. THRESH) THEN
442                  IF (.NOT.PRINTED_GUIDE) THEN
443                     WRITE(*,*)
444                     WRITE( *, 9996) 1
445                     WRITE( *, 9995) 2
446                     WRITE( *, 9994) 3
447                     WRITE( *, 9993) 4
448                     WRITE( *, 9992) 5
449                     WRITE( *, 9991) 6
450                     WRITE( *, 9990) 7
451                     WRITE( *, 9989) 8
452                     WRITE(*,*)
453                     PRINTED_GUIDE = .TRUE.
454                  END IF
455                  WRITE( *, 9999) C2, N, K, NGUAR, CGUAR, I, TSTRAT(I)
456                  NFAIL = NFAIL + 1
457               END IF
458            END DO
459      END DO
460
461c$$$         WRITE(*,*)
462c$$$         WRITE(*,*) 'Normwise Error Bounds'
463c$$$         WRITE(*,*) 'Guaranteed error bound: ',ERRBND(NRHS,nwise_i,bnd_i)
464c$$$         WRITE(*,*) 'Reciprocal condition number: ',ERRBND(NRHS,nwise_i,cond_i)
465c$$$         WRITE(*,*) 'Raw error estimate: ',ERRBND(NRHS,nwise_i,rawbnd_i)
466c$$$         WRITE(*,*)
467c$$$         WRITE(*,*) 'Componentwise Error Bounds'
468c$$$         WRITE(*,*) 'Guaranteed error bound: ',ERRBND(NRHS,cwise_i,bnd_i)
469c$$$         WRITE(*,*) 'Reciprocal condition number: ',ERRBND(NRHS,cwise_i,cond_i)
470c$$$         WRITE(*,*) 'Raw error estimate: ',ERRBND(NRHS,cwise_i,rawbnd_i)
471c$$$         print *, 'Info: ', info
472c$$$         WRITE(*,*)
473*         WRITE(*,*) 'TSTRAT: ',TSTRAT
474
475      END DO
476
477      WRITE(*,*)
478      IF( NFAIL .GT. 0 ) THEN
479         WRITE(*,9998) C2, NFAIL, NTESTS*N+N_AUX_TESTS
480      ELSE
481         WRITE(*,9997) C2
482      END IF
483 9999 FORMAT( ' Z', A2, 'SVXX: N =', I2, ', RHS = ', I2,
484     $     ', NWISE GUAR. = ', A, ', CWISE GUAR. = ', A,
485     $     ' test(',I1,') =', G12.5 )
486 9998 FORMAT( ' Z', A2, 'SVXX: ', I6, ' out of ', I6,
487     $     ' tests failed to pass the threshold' )
488 9997 FORMAT( ' Z', A2, 'SVXX passed the tests of error bounds' )
489*     Test ratios.
490 9996 FORMAT( 3X, I2, ': Normwise guaranteed forward error', / 5X,
491     $     'Guaranteed case: if norm ( abs( Xc - Xt )',
492     $     ' / norm ( Xt ) .LE. ERRBND( *, nwise_i, bnd_i ), then',
493     $     / 5X,
494     $     'ERRBND( *, nwise_i, bnd_i ) .LE. MAX(SQRT(N), 10) * EPS')
495 9995 FORMAT( 3X, I2, ': Componentwise guaranteed forward error' )
496 9994 FORMAT( 3X, I2, ': Backwards error' )
497 9993 FORMAT( 3X, I2, ': Reciprocal condition number' )
498 9992 FORMAT( 3X, I2, ': Reciprocal normwise condition number' )
499 9991 FORMAT( 3X, I2, ': Raw normwise error estimate' )
500 9990 FORMAT( 3X, I2, ': Reciprocal componentwise condition number' )
501 9989 FORMAT( 3X, I2, ': Raw componentwise error estimate' )
502
503 8000 FORMAT( ' Z', A2, 'SVXX: N =', I2, ', INFO = ', I3,
504     $     ', ORCOND = ', G12.5, ', real RCOND = ', G12.5 )
505*
506*     End of ZEBCHVXX
507*
508      END
509