1       SUBROUTINE SDRVLS( DOTYPE, NM, MVAL, NN, NVAL, NNS, NSVAL, NNB,
  2      $                   NBVAL, NXVAL, THRESH, TSTERR, A, COPYA, B,
  3      $                   COPYB, C, S, COPYS, WORK, 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       REAL               THRESH
 13 *     ..
 14 *     .. Array Arguments ..
 15       LOGICAL            DOTYPE( * )
 16       INTEGER            IWORK( * ), MVAL( * ), NBVAL( * ), NSVAL( * ),
 17      $                   NVAL( * ), NXVAL( * )
 18       REAL               A( * ), B( * ), C( * ), COPYA( * ), COPYB( * ),
 19      $                   COPYS( * ), S( * ), WORK( * )
 20 *     ..
 21 *
 22 *  Purpose
 23 *  =======
 24 *
 25 *  SDRVLS tests the least squares driver routines SGELS, SGELSS, SGELSX,
 26 *  SGELSY and SGELSD.
 27 *
 28 *  Arguments
 29 *  =========
 30 *
 31 *  DOTYPE  (input) LOGICAL array, dimension (NTYPES)
 32 *          The matrix types to be used for testing.  Matrices of type j
 33 *          (for 1 <= j <= NTYPES) are used for testing if DOTYPE(j) =
 34 *          .TRUE.; if DOTYPE(j) = .FALSE., then type j is not used.
 35 *          The matrix of type j is generated as follows:
 36 *          j=1: A = U*D*V where U and V are random orthogonal matrices
 37 *               and D has random entries (> 0.1) taken from a uniform 
 38 *               distribution (0,1). A is full rank.
 39 *          j=2: The same of 1, but A is scaled up.
 40 *          j=3: The same of 1, but A is scaled down.
 41 *          j=4: A = U*D*V where U and V are random orthogonal matrices
 42 *               and D has 3*min(M,N)/4 random entries (> 0.1) taken
 43 *               from a uniform distribution (0,1) and the remaining
 44 *               entries set to 0. A is rank-deficient. 
 45 *          j=5: The same of 4, but A is scaled up.
 46 *          j=6: The same of 5, but A is scaled down.
 47 *
 48 *  NM      (input) INTEGER
 49 *          The number of values of M contained in the vector MVAL.
 50 *
 51 *  MVAL    (input) INTEGER array, dimension (NM)
 52 *          The values of the matrix row dimension M.
 53 *
 54 *  NN      (input) INTEGER
 55 *          The number of values of N contained in the vector NVAL.
 56 *
 57 *  NVAL    (input) INTEGER array, dimension (NN)
 58 *          The values of the matrix column dimension N.
 59 *
 60 *  NNS     (input) INTEGER
 61 *          The number of values of NRHS contained in the vector NSVAL.
 62 *
 63 *  NSVAL   (input) INTEGER array, dimension (NNS)
 64 *          The values of the number of right hand sides NRHS.
 65 *
 66 *  NNB     (input) INTEGER
 67 *          The number of values of NB and NX contained in the
 68 *          vectors NBVAL and NXVAL.  The blocking parameters are used
 69 *          in pairs (NB,NX).
 70 *
 71 *  NBVAL   (input) INTEGER array, dimension (NNB)
 72 *          The values of the blocksize NB.
 73 *
 74 *  NXVAL   (input) INTEGER array, dimension (NNB)
 75 *          The values of the crossover point NX.
 76 *
 77 *  THRESH  (input) REAL
 78 *          The threshold value for the test ratios.  A result is
 79 *          included in the output file if RESULT >= THRESH.  To have
 80 *          every test ratio printed, use THRESH = 0.
 81 *
 82 *  TSTERR  (input) LOGICAL
 83 *          Flag that indicates whether error exits are to be tested.
 84 *
 85 *  A       (workspace) REAL array, dimension (MMAX*NMAX)
 86 *          where MMAX is the maximum value of M in MVAL and NMAX is the
 87 *          maximum value of N in NVAL.
 88 *
 89 *  COPYA   (workspace) REAL array, dimension (MMAX*NMAX)
 90 *
 91 *  B       (workspace) REAL array, dimension (MMAX*NSMAX)
 92 *          where MMAX is the maximum value of M in MVAL and NSMAX is the
 93 *          maximum value of NRHS in NSVAL.
 94 *
 95 *  COPYB   (workspace) REAL array, dimension (MMAX*NSMAX)
 96 *
 97 *  C       (workspace) REAL array, dimension (MMAX*NSMAX)
 98 *
 99 *  S       (workspace) REAL array, dimension
100 *                      (min(MMAX,NMAX))
101 *
102 *  COPYS   (workspace) REAL array, dimension
103 *                      (min(MMAX,NMAX))
104 *
105 *  WORK    (workspace) REAL array,
106 *                      dimension (MMAX*NMAX + 4*NMAX + MMAX).
107 *
108 *  IWORK   (workspace) INTEGER array, dimension (15*NMAX)
109 *
110 *  NOUT    (input) INTEGER
111 *          The unit number for output.
112 *
113 *  =====================================================================
114 *
115 *     .. Parameters ..
116       INTEGER            NTESTS
117       PARAMETER          ( NTESTS = 18 )
118       INTEGER            SMLSIZ
119       PARAMETER          ( SMLSIZ = 25 )
120       REAL               ONE, TWO, ZERO
121       PARAMETER          ( ONE = 1.0E0, TWO = 2.0E0, ZERO = 0.0E0 )
122 *     ..
123 *     .. Local Scalars ..
124       CHARACTER          TRANS
125       CHARACTER*3        PATH
126       INTEGER            CRANK, I, IM, IN, INB, INFO, INS, IRANK, 
127      $                   ISCALE, ITRAN, ITYPE, J, K, LDA, LDB, LDWORK, 
128      $                   LWLSY, LWORK, M, MNMIN, N, NB, NCOLS, NERRS, 
129      $                   NFAIL, NLVL, NRHS, NROWS, NRUN, RANK
130       REAL               EPS, NORMA, NORMB, RCOND
131 *     ..
132 *     .. Local Arrays ..
133       INTEGER            ISEED( 4 ), ISEEDY( 4 )
134       REAL               RESULT( NTESTS )
135 *     ..
136 *     .. External Functions ..
137       REAL               SASUM, SLAMCH, SQRT12, SQRT14, SQRT17
138       EXTERNAL           SASUM, SLAMCH, SQRT12, SQRT14, SQRT17
139 *     ..
140 *     .. External Subroutines ..
141       EXTERNAL           ALAERH, ALAHD, ALASVM, SAXPY, SERRLS, SGELS,
142      $                   SGELSD, SGELSS, SGELSX, SGELSY, SGEMM, SLACPY,
143      $                   SLARNV, SQRT13, SQRT15, SQRT16, SSCAL,
144      $                   XLAENV
145 *     ..
146 *     .. Intrinsic Functions ..
147       INTRINSIC          INTLOGMAXMIN, REAL, SQRT
148 *     ..
149 *     .. Scalars in Common ..
150       LOGICAL            LERR, OK
151       CHARACTER*32       SRNAMT
152       INTEGER            INFOT, IOUNIT
153 *     ..
154 *     .. Common blocks ..
155       COMMON             / INFOC / INFOT, IOUNIT, OK, LERR
156       COMMON             / SRNAMC / SRNAMT
157 *     ..
158 *     .. Data statements ..
159       DATA               ISEEDY / 1988198919901991 /
160 *     ..
161 *     .. Executable Statements ..
162 *
163 *     Initialize constants and the random number seed.
164 *
165       PATH( 11 ) = 'Single precision'
166       PATH( 23 ) = 'LS'
167       NRUN = 0
168       NFAIL = 0
169       NERRS = 0
170       DO 10 I = 14
171          ISEED( I ) = ISEEDY( I )
172    10 CONTINUE
173       EPS = SLAMCH( 'Epsilon' )
174 *
175 *     Threshold for rank estimation
176 *
177       RCOND = SQRT( EPS ) - ( SQRT( EPS )-EPS ) / 2
178 *
179 *     Test the error exits
180 *
181       CALL XLAENV( 22 )
182       CALL XLAENV( 9, SMLSIZ )
183       IF( TSTERR )
184      $   CALL SERRLS( PATH, NOUT )
185 *
186 *     Print the header if NM = 0 or NN = 0 and THRESH = 0.
187 *
188       IF( ( NM.EQ.0 .OR. NN.EQ.0 ) .AND. THRESH.EQ.ZERO )
189      $   CALL ALAHD( NOUT, PATH )
190       INFOT = 0
191 *
192       DO 150 IM = 1, NM
193          M = MVAL( IM )
194          LDA = MAX1, M )
195 *
196          DO 140 IN = 1, NN
197             N = NVAL( IN )
198             MNMIN = MIN( M, N )
199             LDB = MAX1, M, N )
200 *
201             DO 130 INS = 1, NNS
202                NRHS = NSVAL( INS )
203                NLVL = MAXINTLOGMAX( ONE, REAL( MNMIN ) ) /
204      $                REAL( SMLSIZ+1 ) ) / LOG( TWO ) ) + 10 )
205                LWORK = MAX1, ( M+NRHS )*( N+2 ), ( N+NRHS )*( M+2 ),
206      $                 M*N+4*MNMIN+MAX( M, N ), 12*MNMIN+2*MNMIN*SMLSIZ+
207      $                 8*MNMIN*NLVL+MNMIN*NRHS+(SMLSIZ+1)**2 )
208 *
209                DO 120 IRANK = 12
210                   DO 110 ISCALE = 13
211                      ITYPE = ( IRANK-1 )*3 + ISCALE
212                      IF.NOT.DOTYPE( ITYPE ) )
213      $                  GO TO 110
214 *
215                      IF( IRANK.EQ.1 ) THEN
216 *
217 *                       Test SGELS
218 *
219 *                       Generate a matrix of scaling type ISCALE
220 *
221                         CALL SQRT13( ISCALE, M, N, COPYA, LDA, NORMA,
222      $                               ISEED )
223                         DO 40 INB = 1, NNB
224                            NB = NBVAL( INB )
225                            CALL XLAENV( 1, NB )
226                            CALL XLAENV( 3, NXVAL( INB ) )
227 *
228                            DO 30 ITRAN = 12
229                               IF( ITRAN.EQ.1 ) THEN
230                                  TRANS = 'N'
231                                  NROWS = M
232                                  NCOLS = N
233                               ELSE
234                                  TRANS = 'T'
235                                  NROWS = N
236                                  NCOLS = M
237                               END IF
238                               LDWORK = MAX1, NCOLS )
239 *
240 *                             Set up a consistent rhs
241 *
242                               IF( NCOLS.GT.0 ) THEN
243                                  CALL SLARNV( 2, ISEED, NCOLS*NRHS,
244      $                                        WORK )
245                                  CALL SSCAL( NCOLS*NRHS,
246      $                                       ONE / REAL( NCOLS ), WORK,
247      $                                       1 )
248                               END IF
249                               CALL SGEMM( TRANS, 'No transpose', NROWS,
250      $                                    NRHS, NCOLS, ONE, COPYA, LDA,
251      $                                    WORK, LDWORK, ZERO, B, LDB )
252                               CALL SLACPY( 'Full', NROWS, NRHS, B, LDB,
253      $                                     COPYB, LDB )
254 *
255 *                             Solve LS or overdetermined system
256 *
257                               IF( M.GT.0 .AND. N.GT.0 ) THEN
258                                  CALL SLACPY( 'Full', M, N, COPYA, LDA,
259      $                                        A, LDA )
260                                  CALL SLACPY( 'Full', NROWS, NRHS,
261      $                                        COPYB, LDB, B, LDB )
262                               END IF
263                               SRNAMT = 'SGELS '
264                               CALL SGELS( TRANS, M, N, NRHS, A, LDA, B,
265      $                                    LDB, WORK, LWORK, INFO )
266                               IF( INFO.NE.0 )
267      $                           CALL ALAERH( PATH, 'SGELS ', INFO, 0,
268      $                                        TRANS, M, N, NRHS, -1, NB,
269      $                                        ITYPE, NFAIL, NERRS,
270      $                                        NOUT )
271 *
272 *                             Check correctness of results
273 *
274                               LDWORK = MAX1, NROWS )
275                               IF( NROWS.GT.0 .AND. NRHS.GT.0 )
276      $                           CALL SLACPY( 'Full', NROWS, NRHS,
277      $                                        COPYB, LDB, C, LDB )
278                               CALL SQRT16( TRANS, M, N, NRHS, COPYA,
279      $                                     LDA, B, LDB, C, LDB, WORK,
280      $                                     RESULT1 ) )
281 *
282                               IF( ( ITRAN.EQ.1 .AND. M.GE.N ) .OR.
283      $                            ( ITRAN.EQ.2 .AND. M.LT.N ) ) THEN
284 *
285 *                                Solving LS system
286 *
287                                  RESULT2 ) = SQRT17( TRANS, 1, M, N,
288      $                                         NRHS, COPYA, LDA, B, LDB,
289      $                                         COPYB, LDB, C, WORK,
290      $                                         LWORK )
291                               ELSE
292 *
293 *                                Solving overdetermined system
294 *
295                                  RESULT2 ) = SQRT14( TRANS, M, N,
296      $                                         NRHS, COPYA, LDA, B, LDB,
297      $                                         WORK, LWORK )
298                               END IF
299 *
300 *                             Print information about the tests that
301 *                             did not pass the threshold.
302 *
303                               DO 20 K = 12
304                                  IFRESULT( K ).GE.THRESH ) THEN
305                                     IF( NFAIL.EQ.0 .AND. NERRS.EQ.0 )
306      $                                 CALL ALAHD( NOUT, PATH )
307                                     WRITE( NOUT, FMT = 9999 )TRANS, M,
308      $                                 N, NRHS, NB, ITYPE, K,
309      $                                 RESULT( K )
310                                     NFAIL = NFAIL + 1
311                                  END IF
312    20                         CONTINUE
313                               NRUN = NRUN + 2
314    30                      CONTINUE
315    40                   CONTINUE
316                      END IF
317 *
318 *                    Generate a matrix of scaling type ISCALE and rank
319 *                    type IRANK.
320 *
321                      CALL SQRT15( ISCALE, IRANK, M, N, NRHS, COPYA, LDA,
322      $                            COPYB, LDB, COPYS, RANK, NORMA, NORMB,
323      $                            ISEED, WORK, LWORK )
324 *
325 *                    workspace used: MAX(M+MIN(M,N),NRHS*MIN(M,N),2*N+M)
326 *
327 *                    Initialize vector IWORK.
328 *
329                      DO 50 J = 1, N
330                         IWORK( J ) = 0
331    50                CONTINUE
332                      LDWORK = MAX1, M )
333 *
334 *                    Test SGELSX
335 *
336 *                    SGELSX:  Compute the minimum-norm solution X
337 *                    to min( norm( A * X - B ) ) using a complete
338 *                    orthogonal factorization.
339 *
340                      CALL SLACPY( 'Full', M, N, COPYA, LDA, A, LDA )
341                      CALL SLACPY( 'Full', M, NRHS, COPYB, LDB, B, LDB )
342 *
343                      SRNAMT = 'SGELSX'
344                      CALL SGELSX( M, N, NRHS, A, LDA, B, LDB, IWORK,
345      $                            RCOND, CRANK, WORK, INFO )
346                      IF( INFO.NE.0 )
347      $                  CALL ALAERH( PATH, 'SGELSX', INFO, 0' ', M, N,
348      $                               NRHS, -1, NB, ITYPE, NFAIL, NERRS,
349      $                               NOUT )
350 *
351 *                    workspace used: MAX( MNMIN+3*N, 2*MNMIN+NRHS )
352 *
353 *                    Test 3:  Compute relative error in svd
354 *                             workspace: M*N + 4*MIN(M,N) + MAX(M,N)
355 *
356                      RESULT3 ) = SQRT12( CRANK, CRANK, A, LDA, COPYS,
357      $                             WORK, LWORK )
358 *
359 *                    Test 4:  Compute error in solution
360 *                             workspace:  M*NRHS + M
361 *
362                      CALL SLACPY( 'Full', M, NRHS, COPYB, LDB, WORK,
363      $                            LDWORK )
364                      CALL SQRT16( 'No transpose', M, N, NRHS, COPYA,
365      $                            LDA, B, LDB, WORK, LDWORK,
366      $                            WORK( M*NRHS+1 ), RESULT4 ) )
367 *
368 *                    Test 5:  Check norm of r'*A
369 *                             workspace: NRHS*(M+N)
370 *
371                      RESULT5 ) = ZERO
372                      IF( M.GT.CRANK )
373      $                  RESULT5 ) = SQRT17( 'No transpose'1, M, N,
374      $                                NRHS, COPYA, LDA, B, LDB, COPYB,
375      $                                LDB, C, WORK, LWORK )
376 *
377 *                    Test 6:  Check if x is in the rowspace of A
378 *                             workspace: (M+NRHS)*(N+2)
379 *
380                      RESULT6 ) = ZERO
381 *
382                      IF( N.GT.CRANK )
383      $                  RESULT6 ) = SQRT14( 'No transpose', M, N,
384      $                                NRHS, COPYA, LDA, B, LDB, WORK,
385      $                                LWORK )
386 *
387 *                    Print information about the tests that did not
388 *                    pass the threshold.
389 *
390                      DO 60 K = 36
391                         IFRESULT( K ).GE.THRESH ) THEN
392                            IF( NFAIL.EQ.0 .AND. NERRS.EQ.0 )
393      $                        CALL ALAHD( NOUT, PATH )
394                            WRITE( NOUT, FMT = 9998 )M, N, NRHS, NB,
395      $                        ITYPE, K, RESULT( K )
396                            NFAIL = NFAIL + 1
397                         END IF
398    60                CONTINUE
399                      NRUN = NRUN + 4
400 *
401 *                    Loop for testing different block sizes.
402 *
403                      DO 100 INB = 1, NNB
404                         NB = NBVAL( INB )
405                         CALL XLAENV( 1, NB )
406                         CALL XLAENV( 3, NXVAL( INB ) )
407 *
408 *                       Test SGELSY
409 *
410 *                       SGELSY:  Compute the minimum-norm solution X
411 *                       to min( norm( A * X - B ) )
412 *                       using the rank-revealing orthogonal
413 *                       factorization.
414 *
415 *                       Initialize vector IWORK.
416 *
417                         DO 70 J = 1, N
418                            IWORK( J ) = 0
419    70                   CONTINUE
420 *
421 *                       Set LWLSY to the adequate value.
422 *
423                         LWLSY = MAX1, MNMIN+2*N+NB*( N+1 ),
424      $                          2*MNMIN+NB*NRHS )
425 *
426                         CALL SLACPY( 'Full', M, N, COPYA, LDA, A, LDA )
427                         CALL SLACPY( 'Full', M, NRHS, COPYB, LDB, B,
428      $                               LDB )
429 *
430                         SRNAMT = 'SGELSY'
431                         CALL SGELSY( M, N, NRHS, A, LDA, B, LDB, IWORK,
432      $                               RCOND, CRANK, WORK, LWLSY, INFO )
433                         IF( INFO.NE.0 )
434      $                     CALL ALAERH( PATH, 'SGELSY', INFO, 0' ', M,
435      $                                  N, NRHS, -1, NB, ITYPE, NFAIL,
436      $                                  NERRS, NOUT )
437 *
438 *                       Test 7:  Compute relative error in svd
439 *                                workspace: M*N + 4*MIN(M,N) + MAX(M,N)
440 *
441                         RESULT7 ) = SQRT12( CRANK, CRANK, A, LDA,
442      $                                COPYS, WORK, LWORK )
443 *
444 *                       Test 8:  Compute error in solution
445 *                                workspace:  M*NRHS + M
446 *
447                         CALL SLACPY( 'Full', M, NRHS, COPYB, LDB, WORK,
448      $                               LDWORK )
449                         CALL SQRT16( 'No transpose', M, N, NRHS, COPYA,
450      $                               LDA, B, LDB, WORK, LDWORK,
451      $                               WORK( M*NRHS+1 ), RESULT8 ) )
452 *
453 *                       Test 9:  Check norm of r'*A
454 *                                workspace: NRHS*(M+N)
455 *
456                         RESULT9 ) = ZERO
457                         IF( M.GT.CRANK )
458      $                     RESULT9 ) = SQRT17( 'No transpose'1, M,
459      $                                   N, NRHS, COPYA, LDA, B, LDB,
460      $                                   COPYB, LDB, C, WORK, LWORK )
461 *
462 *                       Test 10:  Check if x is in the rowspace of A
463 *                                workspace: (M+NRHS)*(N+2)
464 *
465                         RESULT10 ) = ZERO
466 *
467                         IF( N.GT.CRANK )
468      $                     RESULT10 ) = SQRT14( 'No transpose', M, N,
469      $                                    NRHS, COPYA, LDA, B, LDB,
470      $                                    WORK, LWORK )
471 *
472 *                       Test SGELSS
473 *
474 *                       SGELSS:  Compute the minimum-norm solution X
475 *                       to min( norm( A * X - B ) )
476 *                       using the SVD.
477 *
478                         CALL SLACPY( 'Full', M, N, COPYA, LDA, A, LDA )
479                         CALL SLACPY( 'Full', M, NRHS, COPYB, LDB, B,
480      $                               LDB )
481                         SRNAMT = 'SGELSS'
482                         CALL SGELSS( M, N, NRHS, A, LDA, B, LDB, S,
483      $                               RCOND, CRANK, WORK, LWORK, INFO )
484                         IF( INFO.NE.0 )
485      $                     CALL ALAERH( PATH, 'SGELSS', INFO, 0' ', M,
486      $                                  N, NRHS, -1, NB, ITYPE, NFAIL,
487      $                                  NERRS, NOUT )
488 *
489 *                       workspace used: 3*min(m,n) +
490 *                                       max(2*min(m,n),nrhs,max(m,n))
491 *
492 *                       Test 11:  Compute relative error in svd
493 *
494                         IF( RANK.GT.0 ) THEN
495                            CALL SAXPY( MNMIN, -ONE, COPYS, 1, S, 1 )
496                            RESULT11 ) = SASUM( MNMIN, S, 1 ) /
497      $                                    SASUM( MNMIN, COPYS, 1 ) /
498      $                                    ( EPS*REAL( MNMIN ) )
499                         ELSE
500                            RESULT11 ) = ZERO
501                         END IF
502 *
503 *                       Test 12:  Compute error in solution
504 *
505                         CALL SLACPY( 'Full', M, NRHS, COPYB, LDB, WORK,
506      $                               LDWORK )
507                         CALL SQRT16( 'No transpose', M, N, NRHS, COPYA,
508      $                               LDA, B, LDB, WORK, LDWORK,
509      $                               WORK( M*NRHS+1 ), RESULT12 ) )
510 *
511 *                       Test 13:  Check norm of r'*A
512 *
513                         RESULT13 ) = ZERO
514                         IF( M.GT.CRANK )
515      $                     RESULT13 ) = SQRT17( 'No transpose'1, M,
516      $                                    N, NRHS, COPYA, LDA, B, LDB,
517      $                                    COPYB, LDB, C, WORK, LWORK )
518 *
519 *                       Test 14:  Check if x is in the rowspace of A
520 *
521                         RESULT14 ) = ZERO
522                         IF( N.GT.CRANK )
523      $                     RESULT14 ) = SQRT14( 'No transpose', M, N,
524      $                                    NRHS, COPYA, LDA, B, LDB,
525      $                                    WORK, LWORK )
526 *
527 *                       Test SGELSD
528 *
529 *                       SGELSD:  Compute the minimum-norm solution X
530 *                       to min( norm( A * X - B ) ) using a
531 *                       divide and conquer SVD.
532 *
533 *                       Initialize vector IWORK.
534 *
535                         DO 80 J = 1, N
536                            IWORK( J ) = 0
537    80                   CONTINUE
538 *
539                         CALL SLACPY( 'Full', M, N, COPYA, LDA, A, LDA )
540                         CALL SLACPY( 'Full', M, NRHS, COPYB, LDB, B,
541      $                               LDB )
542 *
543                         SRNAMT = 'SGELSD'
544                         CALL SGELSD( M, N, NRHS, A, LDA, B, LDB, S,
545      $                               RCOND, CRANK, WORK, LWORK, IWORK,
546      $                               INFO )
547                         IF( INFO.NE.0 )
548      $                     CALL ALAERH( PATH, 'SGELSD', INFO, 0' ', M,
549      $                                  N, NRHS, -1, NB, ITYPE, NFAIL,
550      $                                  NERRS, NOUT )
551 *
552 *                       Test 15:  Compute relative error in svd
553 *
554                         IF( RANK.GT.0 ) THEN
555                            CALL SAXPY( MNMIN, -ONE, COPYS, 1, S, 1 )
556                            RESULT15 ) = SASUM( MNMIN, S, 1 ) /
557      $                                    SASUM( MNMIN, COPYS, 1 ) /
558      $                                    ( EPS*REAL( MNMIN ) )
559                         ELSE
560                            RESULT15 ) = ZERO
561                         END IF
562 *
563 *                       Test 16:  Compute error in solution
564 *
565                         CALL SLACPY( 'Full', M, NRHS, COPYB, LDB, WORK,
566      $                               LDWORK )
567                         CALL SQRT16( 'No transpose', M, N, NRHS, COPYA,
568      $                               LDA, B, LDB, WORK, LDWORK,
569      $                               WORK( M*NRHS+1 ), RESULT16 ) )
570 *
571 *                       Test 17:  Check norm of r'*A
572 *
573                         RESULT17 ) = ZERO
574                         IF( M.GT.CRANK )
575      $                     RESULT17 ) = SQRT17( 'No transpose'1, M,
576      $                                    N, NRHS, COPYA, LDA, B, LDB,
577      $                                    COPYB, LDB, C, WORK, LWORK )
578 *
579 *                       Test 18:  Check if x is in the rowspace of A
580 *
581                         RESULT18 ) = ZERO
582                         IF( N.GT.CRANK )
583      $                     RESULT18 ) = SQRT14( 'No transpose', M, N,
584      $                                    NRHS, COPYA, LDA, B, LDB,
585      $                                    WORK, LWORK )
586 *
587 *                       Print information about the tests that did not
588 *                       pass the threshold.
589 *
590                         DO 90 K = 7, NTESTS
591                            IFRESULT( K ).GE.THRESH ) THEN
592                               IF( NFAIL.EQ.0 .AND. NERRS.EQ.0 )
593      $                           CALL ALAHD( NOUT, PATH )
594                               WRITE( NOUT, FMT = 9998 )M, N, NRHS, NB,
595      $                           ITYPE, K, RESULT( K )
596                               NFAIL = NFAIL + 1
597                            END IF
598    90                   CONTINUE
599                         NRUN = NRUN + 12 
600 *
601   100                CONTINUE
602   110             CONTINUE
603   120          CONTINUE
604   130       CONTINUE
605   140    CONTINUE
606   150 CONTINUE
607 *
608 *     Print a summary of the results.
609 *
610       CALL ALASVM( PATH, NOUT, NFAIL, NRUN, NERRS )
611 *
612  9999 FORMAT' TRANS=''', A1, ''', M=', I5, ', N=', I5, ', NRHS=', I4,
613      $      ', NB=', I4, ', type', I2, ', test(', I2, ')='G12.5 )
614  9998 FORMAT' M=', I5, ', N=', I5, ', NRHS=', I4, ', NB=', I4,
615      $      ', type', I2, ', test(', I2, ')='G12.5 )
616       RETURN
617 *
618 *     End of SDRVLS
619 *
620       END