1       SUBROUTINE ZDRVLS( DOTYPE, NM, MVAL, NN, NVAL, NNS, NSVAL, NNB,
  2      $                   NBVAL, NXVAL, THRESH, TSTERR, A, COPYA, B,
  3      $                   COPYB, C, S, COPYS, WORK, RWORK, IWORK, NOUT )
  4 *
  5 *  -- LAPACK test routine (version 3.1.1) --
  6 *     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
  7 *     January 2007
  8 *
  9 *     .. Scalar Arguments ..
 10       LOGICAL            TSTERR
 11       INTEGER            NM, NN, NNB, NNS, NOUT
 12       DOUBLE PRECISION   THRESH
 13 *     ..
 14 *     .. Array Arguments ..
 15       LOGICAL            DOTYPE( * )
 16       INTEGER            IWORK( * ), MVAL( * ), NBVAL( * ), NSVAL( * ),
 17      $                   NVAL( * ), NXVAL( * )
 18       DOUBLE PRECISION   COPYS( * ), RWORK( * ), S( * )
 19       COMPLEX*16         A( * ), B( * ), C( * ), COPYA( * ), COPYB( * ),
 20      $                   WORK( * )
 21 *     ..
 22 *
 23 *  Purpose
 24 *  =======
 25 *
 26 *  ZDRVLS tests the least squares driver routines ZGELS, CGELSX, CGELSS,
 27 *  ZGELSY and CGELSD.
 28 *
 29 *  Arguments
 30 *  =========
 31 *
 32 *  DOTYPE  (input) LOGICAL array, dimension (NTYPES)
 33 *          The matrix types to be used for testing.  Matrices of type j
 34 *          (for 1 <= j <= NTYPES) are used for testing if DOTYPE(j) =
 35 *          .TRUE.; if DOTYPE(j) = .FALSE., then type j is not used.
 36 *          The matrix of type j is generated as follows:
 37 *          j=1: A = U*D*V where U and V are random unitary matrices
 38 *               and D has random entries (> 0.1) taken from a uniform
 39 *               distribution (0,1). A is full rank.
 40 *          j=2: The same of 1, but A is scaled up.
 41 *          j=3: The same of 1, but A is scaled down.
 42 *          j=4: A = U*D*V where U and V are random unitary matrices
 43 *               and D has 3*min(M,N)/4 random entries (> 0.1) taken
 44 *               from a uniform distribution (0,1) and the remaining
 45 *               entries set to 0. A is rank-deficient.
 46 *          j=5: The same of 4, but A is scaled up.
 47 *          j=6: The same of 5, but A is scaled down.
 48 *
 49 *  NM      (input) INTEGER
 50 *          The number of values of M contained in the vector MVAL.
 51 *
 52 *  MVAL    (input) INTEGER array, dimension (NM)
 53 *          The values of the matrix row dimension M.
 54 *
 55 *  NN      (input) INTEGER
 56 *          The number of values of N contained in the vector NVAL.
 57 *
 58 *  NVAL    (input) INTEGER array, dimension (NN)
 59 *          The values of the matrix column dimension N.
 60 *
 61 *  NNB     (input) INTEGER
 62 *          The number of values of NB and NX contained in the
 63 *          vectors NBVAL and NXVAL.  The blocking parameters are used
 64 *          in pairs (NB,NX).
 65 *
 66 *  NBVAL   (input) INTEGER array, dimension (NNB)
 67 *          The values of the blocksize NB.
 68 *
 69 *  NXVAL   (input) INTEGER array, dimension (NNB)
 70 *          The values of the crossover point NX.
 71 *
 72 *  NNS     (input) INTEGER
 73 *          The number of values of NRHS contained in the vector NSVAL.
 74 *
 75 *  NSVAL   (input) INTEGER array, dimension (NNS)
 76 *          The values of the number of right hand sides NRHS.
 77 *
 78 *  THRESH  (input) DOUBLE PRECISION
 79 *          The threshold value for the test ratios.  A result is
 80 *          included in the output file if RESULT >= THRESH.  To have
 81 *          every test ratio printed, use THRESH = 0.
 82 *
 83 *  TSTERR  (input) LOGICAL
 84 *          Flag that indicates whether error exits are to be tested.
 85 *
 86 *  A       (workspace) COMPLEX*16 array, dimension (MMAX*NMAX)
 87 *          where MMAX is the maximum value of M in MVAL and NMAX is the
 88 *          maximum value of N in NVAL.
 89 *
 90 *  COPYA   (workspace) COMPLEX*16 array, dimension (MMAX*NMAX)
 91 *
 92 *  B       (workspace) COMPLEX*16 array, dimension (MMAX*NSMAX)
 93 *          where MMAX is the maximum value of M in MVAL and NSMAX is the
 94 *          maximum value of NRHS in NSVAL.
 95 *
 96 *  COPYB   (workspace) COMPLEX*16 array, dimension (MMAX*NSMAX)
 97 *
 98 *  C       (workspace) COMPLEX*16 array, dimension (MMAX*NSMAX)
 99 *
100 *  S       (workspace) DOUBLE PRECISION array, dimension
101 *                      (min(MMAX,NMAX))
102 *
103 *  COPYS   (workspace) DOUBLE PRECISION array, dimension
104 *                      (min(MMAX,NMAX))
105 *
106 *  WORK    (workspace) COMPLEX*16 array, dimension
107 *                      (MMAX*NMAX + 4*NMAX + MMAX).
108 *
109 *  RWORK   (workspace) DOUBLE PRECISION array, dimension (5*NMAX-1)
110 *
111 *  IWORK   (workspace) INTEGER array, dimension (15*NMAX)
112 *
113 *  NOUT    (input) INTEGER
114 *          The unit number for output.
115 *
116 *  =====================================================================
117 *
118 *     .. Parameters ..
119       INTEGER            NTESTS
120       PARAMETER          ( NTESTS = 18 )
121       INTEGER            SMLSIZ
122       PARAMETER          ( SMLSIZ = 25 )
123       DOUBLE PRECISION   ONE, ZERO
124       PARAMETER          ( ONE = 1.0D+0, ZERO = 0.0D+0 )
125       COMPLEX*16         CONE, CZERO
126       PARAMETER          ( CONE = ( 1.0D+00.0D+0 ),
127      $                   CZERO = ( 0.0D+00.0D+0 ) )
128 *     ..
129 *     .. Local Scalars ..
130       CHARACTER          TRANS
131       CHARACTER*3        PATH
132       INTEGER            CRANK, I, IM, IN, INB, INFO, INS, IRANK,
133      $                   ISCALE, ITRAN, ITYPE, J, K, LDA, LDB, LDWORK,
134      $                   LWLSY, LWORK, M, MNMIN, N, NB, NCOLS, NERRS,
135      $                   NFAIL, NRHS, NROWS, NRUN, RANK
136       DOUBLE PRECISION   EPS, NORMA, NORMB, RCOND
137 *     ..
138 *     .. Local Arrays ..
139       INTEGER            ISEED( 4 ), ISEEDY( 4 )
140       DOUBLE PRECISION   RESULT( NTESTS )
141 *     ..
142 *     .. External Functions ..
143       DOUBLE PRECISION   DASUM, DLAMCH, ZQRT12, ZQRT14, ZQRT17
144       EXTERNAL           DASUM, DLAMCH, ZQRT12, ZQRT14, ZQRT17
145 *     ..
146 *     .. External Subroutines ..
147       EXTERNAL           ALAERH, ALAHD, ALASVM, DAXPY, DLASRT, XLAENV,
148      $                   ZDSCAL, ZERRLS, ZGELS, ZGELSD, ZGELSS, ZGELSX,
149      $                   ZGELSY, ZGEMM, ZLACPY, ZLARNV, ZQRT13, ZQRT15,
150      $                   ZQRT16
151 *     ..
152 *     .. Intrinsic Functions ..
153       INTRINSIC          DBLEMAXMINSQRT
154 *     ..
155 *     .. Scalars in Common ..
156       LOGICAL            LERR, OK
157       CHARACTER*32       SRNAMT
158       INTEGER            INFOT, IOUNIT
159 *     ..
160 *     .. Common blocks ..
161       COMMON             / INFOC / INFOT, IOUNIT, OK, LERR
162       COMMON             / SRNAMC / SRNAMT
163 *     ..
164 *     .. Data statements ..
165       DATA               ISEEDY / 1988198919901991 /
166 *     ..
167 *     .. Executable Statements ..
168 *
169 *     Initialize constants and the random number seed.
170 *
171       PATH( 11 ) = 'Zomplex precision'
172       PATH( 23 ) = 'LS'
173       NRUN = 0
174       NFAIL = 0
175       NERRS = 0
176       DO 10 I = 14
177          ISEED( I ) = ISEEDY( I )
178    10 CONTINUE
179       EPS = DLAMCH( 'Epsilon' )
180 *
181 *     Threshold for rank estimation
182 *
183       RCOND = SQRT( EPS ) - ( SQRT( EPS )-EPS ) / 2
184 *
185 *     Test the error exits
186 *
187       CALL XLAENV( 9, SMLSIZ )
188       IF( TSTERR )
189      $   CALL ZERRLS( PATH, NOUT )
190 *
191 *     Print the header if NM = 0 or NN = 0 and THRESH = 0.
192 *
193       IF( ( NM.EQ.0 .OR. NN.EQ.0 ) .AND. THRESH.EQ.ZERO )
194      $   CALL ALAHD( NOUT, PATH )
195       INFOT = 0
196 *
197       DO 140 IM = 1, NM
198          M = MVAL( IM )
199          LDA = MAX1, M )
200 *
201          DO 130 IN = 1, NN
202             N = NVAL( IN )
203             MNMIN = MIN( M, N )
204             LDB = MAX1, M, N )
205 *
206             DO 120 INS = 1, NNS
207                NRHS = NSVAL( INS )
208                LWORK = MAX1, ( M+NRHS )*( N+2 ), ( N+NRHS )*( M+2 ),
209      $                 M*N+4*MNMIN+MAX( M, N ), 2*N+M )
210 *
211                DO 110 IRANK = 12
212                   DO 100 ISCALE = 13
213                      ITYPE = ( IRANK-1 )*3 + ISCALE
214                      IF.NOT.DOTYPE( ITYPE ) )
215      $                  GO TO 100
216 *
217                      IF( IRANK.EQ.1 ) THEN
218 *
219 *                       Test ZGELS
220 *
221 *                       Generate a matrix of scaling type ISCALE
222 *
223                         CALL ZQRT13( ISCALE, M, N, COPYA, LDA, NORMA,
224      $                               ISEED )
225                         DO 40 INB = 1, NNB
226                            NB = NBVAL( INB )
227                            CALL XLAENV( 1, NB )
228                            CALL XLAENV( 3, NXVAL( INB ) )
229 *
230                            DO 30 ITRAN = 12
231                               IF( ITRAN.EQ.1 ) THEN
232                                  TRANS = 'N'
233                                  NROWS = M
234                                  NCOLS = N
235                               ELSE
236                                  TRANS = 'C'
237                                  NROWS = N
238                                  NCOLS = M
239                               END IF
240                               LDWORK = MAX1, NCOLS )
241 *
242 *                             Set up a consistent rhs
243 *
244                               IF( NCOLS.GT.0 ) THEN
245                                  CALL ZLARNV( 2, ISEED, NCOLS*NRHS,
246      $                                        WORK )
247                                  CALL ZDSCAL( NCOLS*NRHS,
248      $                                        ONE / DBLE( NCOLS ), WORK,
249      $                                        1 )
250                               END IF
251                               CALL ZGEMM( TRANS, 'No transpose', NROWS,
252      $                                    NRHS, NCOLS, CONE, COPYA, LDA,
253      $                                    WORK, LDWORK, CZERO, B, LDB )
254                               CALL ZLACPY( 'Full', NROWS, NRHS, B, LDB,
255      $                                     COPYB, LDB )
256 *
257 *                             Solve LS or overdetermined system
258 *
259                               IF( M.GT.0 .AND. N.GT.0 ) THEN
260                                  CALL ZLACPY( 'Full', M, N, COPYA, LDA,
261      $                                        A, LDA )
262                                  CALL ZLACPY( 'Full', NROWS, NRHS,
263      $                                        COPYB, LDB, B, LDB )
264                               END IF
265                               SRNAMT = 'ZGELS '
266                               CALL ZGELS( TRANS, M, N, NRHS, A, LDA, B,
267      $                                    LDB, WORK, LWORK, INFO )
268 *
269                               IF( INFO.NE.0 )
270      $                           CALL ALAERH( PATH, 'ZGELS ', INFO, 0,
271      $                                        TRANS, M, N, NRHS, -1, NB,
272      $                                        ITYPE, NFAIL, NERRS,
273      $                                        NOUT )
274 *
275 *                             Check correctness of results
276 *
277                               LDWORK = MAX1, NROWS )
278                               IF( NROWS.GT.0 .AND. NRHS.GT.0 )
279      $                           CALL ZLACPY( 'Full', NROWS, NRHS,
280      $                                        COPYB, LDB, C, LDB )
281                               CALL ZQRT16( TRANS, M, N, NRHS, COPYA,
282      $                                     LDA, B, LDB, C, LDB, RWORK,
283      $                                     RESULT1 ) )
284 *
285                               IF( ( ITRAN.EQ.1 .AND. M.GE.N ) .OR.
286      $                            ( ITRAN.EQ.2 .AND. M.LT.N ) ) THEN
287 *
288 *                                Solving LS system
289 *
290                                  RESULT2 ) = ZQRT17( TRANS, 1, M, N,
291      $                                         NRHS, COPYA, LDA, B, LDB,
292      $                                         COPYB, LDB, C, WORK,
293      $                                         LWORK )
294                               ELSE
295 *
296 *                                Solving overdetermined system
297 *
298                                  RESULT2 ) = ZQRT14( TRANS, M, N,
299      $                                         NRHS, COPYA, LDA, B, LDB,
300      $                                         WORK, LWORK )
301                               END IF
302 *
303 *                             Print information about the tests that
304 *                             did not pass the threshold.
305 *
306                               DO 20 K = 12
307                                  IFRESULT( K ).GE.THRESH ) THEN
308                                     IF( NFAIL.EQ.0 .AND. NERRS.EQ.0 )
309      $                                 CALL ALAHD( NOUT, PATH )
310                                     WRITE( NOUT, FMT = 9999 )TRANS, M,
311      $                                 N, NRHS, NB, ITYPE, K,
312      $                                 RESULT( K )
313                                     NFAIL = NFAIL + 1
314                                  END IF
315    20                         CONTINUE
316                               NRUN = NRUN + 2
317    30                      CONTINUE
318    40                   CONTINUE
319                      END IF
320 *
321 *                    Generate a matrix of scaling type ISCALE and rank
322 *                    type IRANK.
323 *
324                      CALL ZQRT15( ISCALE, IRANK, M, N, NRHS, COPYA, LDA,
325      $                            COPYB, LDB, COPYS, RANK, NORMA, NORMB,
326      $                            ISEED, WORK, LWORK )
327 *
328 *                    workspace used: MAX(M+MIN(M,N),NRHS*MIN(M,N),2*N+M)
329 *
330                      DO 50 J = 1, N
331                         IWORK( J ) = 0
332    50                CONTINUE
333                      LDWORK = MAX1, M )
334 *
335 *                    Test ZGELSX
336 *
337 *                    ZGELSX:  Compute the minimum-norm solution X
338 *                    to min( norm( A * X - B ) )
339 *                    using a complete orthogonal factorization.
340 *
341                      CALL ZLACPY( 'Full', M, N, COPYA, LDA, A, LDA )
342                      CALL ZLACPY( 'Full', M, NRHS, COPYB, LDB, B, LDB )
343 *
344                      SRNAMT = 'ZGELSX'
345                      CALL ZGELSX( M, N, NRHS, A, LDA, B, LDB, IWORK,
346      $                            RCOND, CRANK, WORK, RWORK, INFO )
347 *
348                      IF( INFO.NE.0 )
349      $                  CALL ALAERH( PATH, 'ZGELSX', INFO, 0' ', M, N,
350      $                               NRHS, -1, NB, ITYPE, NFAIL, NERRS,
351      $                               NOUT )
352 *
353 *                    workspace used: MAX( MNMIN+3*N, 2*MNMIN+NRHS )
354 *
355 *                    Test 3:  Compute relative error in svd
356 *                             workspace: M*N + 4*MIN(M,N) + MAX(M,N)
357 *
358                      RESULT3 ) = ZQRT12( CRANK, CRANK, A, LDA, COPYS,
359      $                             WORK, LWORK, RWORK )
360 *
361 *                    Test 4:  Compute error in solution
362 *                             workspace:  M*NRHS + M
363 *
364                      CALL ZLACPY( 'Full', M, NRHS, COPYB, LDB, WORK,
365      $                            LDWORK )
366                      CALL ZQRT16( 'No transpose', M, N, NRHS, COPYA,
367      $                            LDA, B, LDB, WORK, LDWORK, RWORK,
368      $                            RESULT4 ) )
369 *
370 *                    Test 5:  Check norm of r'*A
371 *                             workspace: NRHS*(M+N)
372 *
373                      RESULT5 ) = ZERO
374                      IF( M.GT.CRANK )
375      $                  RESULT5 ) = ZQRT17( 'No transpose'1, M, N,
376      $                                NRHS, COPYA, LDA, B, LDB, COPYB,
377      $                                LDB, C, WORK, LWORK )
378 *
379 *                    Test 6:  Check if x is in the rowspace of A
380 *                             workspace: (M+NRHS)*(N+2)
381 *
382                      RESULT6 ) = ZERO
383 *
384                      IF( N.GT.CRANK )
385      $                  RESULT6 ) = ZQRT14( 'No transpose', M, N,
386      $                                NRHS, COPYA, LDA, B, LDB, WORK,
387      $                                LWORK )
388 *
389 *                    Print information about the tests that did not
390 *                    pass the threshold.
391 *
392                      DO 60 K = 36
393                         IFRESULT( K ).GE.THRESH ) THEN
394                            IF( NFAIL.EQ.0 .AND. NERRS.EQ.0 )
395      $                        CALL ALAHD( NOUT, PATH )
396                            WRITE( NOUT, FMT = 9998 )M, N, NRHS, 0,
397      $                        ITYPE, K, RESULT( K )
398                            NFAIL = NFAIL + 1
399                         END IF
400    60                CONTINUE
401                      NRUN = NRUN + 4
402 *
403 *                    Loop for testing different block sizes.
404 *
405                      DO 90 INB = 1, NNB
406                         NB = NBVAL( INB )
407                         CALL XLAENV( 1, NB )
408                         CALL XLAENV( 3, NXVAL( INB ) )
409 *
410 *                       Test ZGELSY
411 *
412 *                       ZGELSY:  Compute the minimum-norm solution
413 *                       X to min( norm( A * X - B ) )
414 *                       using the rank-revealing orthogonal
415 *                       factorization.
416 *
417                         CALL ZLACPY( 'Full', M, N, COPYA, LDA, A, LDA )
418                         CALL ZLACPY( 'Full', M, NRHS, COPYB, LDB, B,
419      $                               LDB )
420 *
421 *                       Initialize vector IWORK.
422 *
423                         DO 70 J = 1, N
424                            IWORK( J ) = 0
425    70                   CONTINUE
426 *
427 *                       Set LWLSY to the adequate value.
428 *
429                         LWLSY = MNMIN + MAX2*MNMIN, NB*( N+1 ),
430      $                          MNMIN+NB*NRHS )
431                         LWLSY = MAX1, LWLSY )
432 *
433                         SRNAMT = 'ZGELSY'
434                         CALL ZGELSY( M, N, NRHS, A, LDA, B, LDB, IWORK,
435      $                               RCOND, CRANK, WORK, LWLSY, RWORK,
436      $                               INFO )
437                         IF( INFO.NE.0 )
438      $                     CALL ALAERH( PATH, 'ZGELSY', INFO, 0' ', M,
439      $                                  N, NRHS, -1, NB, ITYPE, NFAIL,
440      $                                  NERRS, NOUT )
441 *
442 *                       workspace used: 2*MNMIN+NB*NB+NB*MAX(N,NRHS)
443 *
444 *                       Test 7:  Compute relative error in svd
445 *                                workspace: M*N + 4*MIN(M,N) + MAX(M,N)
446 *
447                         RESULT7 ) = ZQRT12( CRANK, CRANK, A, LDA,
448      $                                COPYS, WORK, LWORK, RWORK )
449 *
450 *                       Test 8:  Compute error in solution
451 *                                workspace:  M*NRHS + M
452 *
453                         CALL ZLACPY( 'Full', M, NRHS, COPYB, LDB, WORK,
454      $                               LDWORK )
455                         CALL ZQRT16( 'No transpose', M, N, NRHS, COPYA,
456      $                               LDA, B, LDB, WORK, LDWORK, RWORK,
457      $                               RESULT8 ) )
458 *
459 *                       Test 9:  Check norm of r'*A
460 *                                workspace: NRHS*(M+N)
461 *
462                         RESULT9 ) = ZERO
463                         IF( M.GT.CRANK )
464      $                     RESULT9 ) = ZQRT17( 'No transpose'1, M,
465      $                                   N, NRHS, COPYA, LDA, B, LDB,
466      $                                   COPYB, LDB, C, WORK, LWORK )
467 *
468 *                       Test 10:  Check if x is in the rowspace of A
469 *                                workspace: (M+NRHS)*(N+2)
470 *
471                         RESULT10 ) = ZERO
472 *
473                         IF( N.GT.CRANK )
474      $                     RESULT10 ) = ZQRT14( 'No transpose', M, N,
475      $                                    NRHS, COPYA, LDA, B, LDB,
476      $                                    WORK, LWORK )
477 *
478 *                       Test ZGELSS
479 *
480 *                       ZGELSS:  Compute the minimum-norm solution
481 *                       X to min( norm( A * X - B ) )
482 *                       using the SVD.
483 *
484                         CALL ZLACPY( 'Full', M, N, COPYA, LDA, A, LDA )
485                         CALL ZLACPY( 'Full', M, NRHS, COPYB, LDB, B,
486      $                               LDB )
487                         SRNAMT = 'ZGELSS'
488                         CALL ZGELSS( M, N, NRHS, A, LDA, B, LDB, S,
489      $                               RCOND, CRANK, WORK, LWORK, RWORK,
490      $                               INFO )
491 *
492                         IF( INFO.NE.0 )
493      $                     CALL ALAERH( PATH, 'ZGELSS', INFO, 0' ', M,
494      $                                  N, NRHS, -1, NB, ITYPE, NFAIL,
495      $                                  NERRS, NOUT )
496 *
497 *                       workspace used: 3*min(m,n) +
498 *                                       max(2*min(m,n),nrhs,max(m,n))
499 *
500 *                       Test 11:  Compute relative error in svd
501 *
502                         IF( RANK.GT.0 ) THEN
503                            CALL DAXPY( MNMIN, -ONE, COPYS, 1, S, 1 )
504                            RESULT11 ) = DASUM( MNMIN, S, 1 ) /
505      $                                    DASUM( MNMIN, COPYS, 1 ) /
506      $                                    ( EPS*DBLE( MNMIN ) )
507                         ELSE
508                            RESULT11 ) = ZERO
509                         END IF
510 *
511 *                       Test 12:  Compute error in solution
512 *
513                         CALL ZLACPY( 'Full', M, NRHS, COPYB, LDB, WORK,
514      $                               LDWORK )
515                         CALL ZQRT16( 'No transpose', M, N, NRHS, COPYA,
516      $                               LDA, B, LDB, WORK, LDWORK, RWORK,
517      $                               RESULT12 ) )
518 *
519 *                       Test 13:  Check norm of r'*A
520 *
521                         RESULT13 ) = ZERO
522                         IF( M.GT.CRANK )
523      $                     RESULT13 ) = ZQRT17( 'No transpose'1, M,
524      $                                    N, NRHS, COPYA, LDA, B, LDB,
525      $                                    COPYB, LDB, C, WORK, LWORK )
526 *
527 *                       Test 14:  Check if x is in the rowspace of A
528 *
529                         RESULT14 ) = ZERO
530                         IF( N.GT.CRANK )
531      $                     RESULT14 ) = ZQRT14( 'No transpose', M, N,
532      $                                    NRHS, COPYA, LDA, B, LDB,
533      $                                    WORK, LWORK )
534 *
535 *                       Test ZGELSD
536 *
537 *                       ZGELSD:  Compute the minimum-norm solution X
538 *                       to min( norm( A * X - B ) ) using a
539 *                       divide and conquer SVD.
540 *
541                         CALL XLAENV( 925 )
542 *
543                         CALL ZLACPY( 'Full', M, N, COPYA, LDA, A, LDA )
544                         CALL ZLACPY( 'Full', M, NRHS, COPYB, LDB, B,
545      $                               LDB )
546 *
547                         SRNAMT = 'ZGELSD'
548                         CALL ZGELSD( M, N, NRHS, A, LDA, B, LDB, S,
549      $                               RCOND, CRANK, WORK, LWORK, RWORK,
550      $                               IWORK, INFO )
551                         IF( INFO.NE.0 )
552      $                     CALL ALAERH( PATH, 'ZGELSD', INFO, 0' ', M,
553      $                                  N, NRHS, -1, NB, ITYPE, NFAIL,
554      $                                  NERRS, NOUT )
555 *
556 *                       Test 15:  Compute relative error in svd
557 *
558                         IF( RANK.GT.0 ) THEN
559                            CALL DAXPY( MNMIN, -ONE, COPYS, 1, S, 1 )
560                            RESULT15 ) = DASUM( MNMIN, S, 1 ) /
561      $                                    DASUM( MNMIN, COPYS, 1 ) /
562      $                                    ( EPS*DBLE( MNMIN ) )
563                         ELSE
564                            RESULT15 ) = ZERO
565                         END IF
566 *
567 *                       Test 16:  Compute error in solution
568 *
569                         CALL ZLACPY( 'Full', M, NRHS, COPYB, LDB, WORK,
570      $                               LDWORK )
571                         CALL ZQRT16( 'No transpose', M, N, NRHS, COPYA,
572      $                               LDA, B, LDB, WORK, LDWORK, RWORK,
573      $                               RESULT16 ) )
574 *
575 *                       Test 17:  Check norm of r'*A
576 *
577                         RESULT17 ) = ZERO
578                         IF( M.GT.CRANK )
579      $                     RESULT17 ) = ZQRT17( 'No transpose'1, M,
580      $                                    N, NRHS, COPYA, LDA, B, LDB,
581      $                                    COPYB, LDB, C, WORK, LWORK )
582 *
583 *                       Test 18:  Check if x is in the rowspace of A
584 *
585                         RESULT18 ) = ZERO
586                         IF( N.GT.CRANK )
587      $                     RESULT18 ) = ZQRT14( 'No transpose', M, N,
588      $                                    NRHS, COPYA, LDA, B, LDB,
589      $                                    WORK, LWORK )
590 *
591 *                       Print information about the tests that did not
592 *                       pass the threshold.
593 *
594                         DO 80 K = 7, NTESTS
595                            IFRESULT( K ).GE.THRESH ) THEN
596                               IF( NFAIL.EQ.0 .AND. NERRS.EQ.0 )
597      $                           CALL ALAHD( NOUT, PATH )
598                               WRITE( NOUT, FMT = 9998 )M, N, NRHS, NB,
599      $                           ITYPE, K, RESULT( K )
600                               NFAIL = NFAIL + 1
601                            END IF
602    80                   CONTINUE
603                         NRUN = NRUN + 12
604 *
605    90                CONTINUE
606   100             CONTINUE
607   110          CONTINUE
608   120       CONTINUE
609   130    CONTINUE
610   140 CONTINUE
611 *
612 *     Print a summary of the results.
613 *
614       CALL ALASVM( PATH, NOUT, NFAIL, NRUN, NERRS )
615 *
616  9999 FORMAT' TRANS=''', A1, ''', M=', I5, ', N=', I5, ', NRHS=', I4,
617      $      ', NB=', I4, ', type', I2, ', test(', I2, ')='G12.5 )
618  9998 FORMAT' M=', I5, ', N=', I5, ', NRHS=', I4, ', NB=', I4,
619      $      ', type', I2, ', test(', I2, ')='G12.5 )
620       RETURN
621 *
622 *     End of ZDRVLS
623 *
624       END