1*> \brief \b ZDRGES
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 ZDRGES( NSIZES, NN, NTYPES, DOTYPE, ISEED, THRESH,
12*                          NOUNIT, A, LDA, B, S, T, Q, LDQ, Z, ALPHA,
13*                          BETA, WORK, LWORK, RWORK, RESULT, BWORK, INFO )
14*
15*       .. Scalar Arguments ..
16*       INTEGER            INFO, LDA, LDQ, LWORK, NOUNIT, NSIZES, NTYPES
17*       DOUBLE PRECISION   THRESH
18*       ..
19*       .. Array Arguments ..
20*       LOGICAL            BWORK( * ), DOTYPE( * )
21*       INTEGER            ISEED( 4 ), NN( * )
22*       DOUBLE PRECISION   RESULT( 13 ), RWORK( * )
23*       COMPLEX*16         A( LDA, * ), ALPHA( * ), B( LDA, * ),
24*      $                   BETA( * ), Q( LDQ, * ), S( LDA, * ),
25*      $                   T( LDA, * ), WORK( * ), Z( LDQ, * )
26*       ..
27*
28*
29*> \par Purpose:
30*  =============
31*>
32*> \verbatim
33*>
34*> ZDRGES checks the nonsymmetric generalized eigenvalue (Schur form)
35*> problem driver ZGGES.
36*>
37*> ZGGES factors A and B as Q*S*Z'  and Q*T*Z' , where ' means conjugate
38*> transpose, S and T are  upper triangular (i.e., in generalized Schur
39*> form), and Q and Z are unitary. It also computes the generalized
40*> eigenvalues (alpha(j),beta(j)), j=1,...,n.  Thus,
41*> w(j) = alpha(j)/beta(j) is a root of the characteristic equation
42*>
43*>                 det( A - w(j) B ) = 0
44*>
45*> Optionally it also reorder the eigenvalues so that a selected
46*> cluster of eigenvalues appears in the leading diagonal block of the
47*> Schur forms.
48*>
49*> When ZDRGES is called, a number of matrix "sizes" ("N's") and a
50*> number of matrix "TYPES" are specified.  For each size ("N")
51*> and each TYPE of matrix, a pair of matrices (A, B) will be generated
52*> and used for testing. For each matrix pair, the following 13 tests
53*> will be performed and compared with the threshhold THRESH except
54*> the tests (5), (11) and (13).
55*>
56*>
57*> (1)   | A - Q S Z' | / ( |A| n ulp ) (no sorting of eigenvalues)
58*>
59*>
60*> (2)   | B - Q T Z' | / ( |B| n ulp ) (no sorting of eigenvalues)
61*>
62*>
63*> (3)   | I - QQ' | / ( n ulp ) (no sorting of eigenvalues)
64*>
65*>
66*> (4)   | I - ZZ' | / ( n ulp ) (no sorting of eigenvalues)
67*>
68*> (5)   if A is in Schur form (i.e. triangular form) (no sorting of
69*>       eigenvalues)
70*>
71*> (6)   if eigenvalues = diagonal elements of the Schur form (S, T),
72*>       i.e., test the maximum over j of D(j)  where:
73*>
74*>                     |alpha(j) - S(j,j)|        |beta(j) - T(j,j)|
75*>           D(j) = ------------------------ + -----------------------
76*>                  max(|alpha(j)|,|S(j,j)|)   max(|beta(j)|,|T(j,j)|)
77*>
78*>       (no sorting of eigenvalues)
79*>
80*> (7)   | (A,B) - Q (S,T) Z' | / ( |(A,B)| n ulp )
81*>       (with sorting of eigenvalues).
82*>
83*> (8)   | I - QQ' | / ( n ulp ) (with sorting of eigenvalues).
84*>
85*> (9)   | I - ZZ' | / ( n ulp ) (with sorting of eigenvalues).
86*>
87*> (10)  if A is in Schur form (i.e. quasi-triangular form)
88*>       (with sorting of eigenvalues).
89*>
90*> (11)  if eigenvalues = diagonal elements of the Schur form (S, T),
91*>       i.e. test the maximum over j of D(j)  where:
92*>
93*>                     |alpha(j) - S(j,j)|        |beta(j) - T(j,j)|
94*>           D(j) = ------------------------ + -----------------------
95*>                  max(|alpha(j)|,|S(j,j)|)   max(|beta(j)|,|T(j,j)|)
96*>
97*>       (with sorting of eigenvalues).
98*>
99*> (12)  if sorting worked and SDIM is the number of eigenvalues
100*>       which were CELECTed.
101*>
102*> Test Matrices
103*> =============
104*>
105*> The sizes of the test matrices are specified by an array
106*> NN(1:NSIZES); the value of each element NN(j) specifies one size.
107*> The "types" are specified by a logical array DOTYPE( 1:NTYPES ); if
108*> DOTYPE(j) is .TRUE., then matrix type "j" will be generated.
109*> Currently, the list of possible types is:
110*>
111*> (1)  ( 0, 0 )         (a pair of zero matrices)
112*>
113*> (2)  ( I, 0 )         (an identity and a zero matrix)
114*>
115*> (3)  ( 0, I )         (an identity and a zero matrix)
116*>
117*> (4)  ( I, I )         (a pair of identity matrices)
118*>
119*>         t   t
120*> (5)  ( J , J  )       (a pair of transposed Jordan blocks)
121*>
122*>                                     t                ( I   0  )
123*> (6)  ( X, Y )         where  X = ( J   0  )  and Y = (      t )
124*>                                  ( 0   I  )          ( 0   J  )
125*>                       and I is a k x k identity and J a (k+1)x(k+1)
126*>                       Jordan block; k=(N-1)/2
127*>
128*> (7)  ( D, I )         where D is diag( 0, 1,..., N-1 ) (a diagonal
129*>                       matrix with those diagonal entries.)
130*> (8)  ( I, D )
131*>
132*> (9)  ( big*D, small*I ) where "big" is near overflow and small=1/big
133*>
134*> (10) ( small*D, big*I )
135*>
136*> (11) ( big*I, small*D )
137*>
138*> (12) ( small*I, big*D )
139*>
140*> (13) ( big*D, big*I )
141*>
142*> (14) ( small*D, small*I )
143*>
144*> (15) ( D1, D2 )        where D1 is diag( 0, 0, 1, ..., N-3, 0 ) and
145*>                        D2 is diag( 0, N-3, N-4,..., 1, 0, 0 )
146*>           t   t
147*> (16) Q ( J , J ) Z     where Q and Z are random orthogonal matrices.
148*>
149*> (17) Q ( T1, T2 ) Z    where T1 and T2 are upper triangular matrices
150*>                        with random O(1) entries above the diagonal
151*>                        and diagonal entries diag(T1) =
152*>                        ( 0, 0, 1, ..., N-3, 0 ) and diag(T2) =
153*>                        ( 0, N-3, N-4,..., 1, 0, 0 )
154*>
155*> (18) Q ( T1, T2 ) Z    diag(T1) = ( 0, 0, 1, 1, s, ..., s, 0 )
156*>                        diag(T2) = ( 0, 1, 0, 1,..., 1, 0 )
157*>                        s = machine precision.
158*>
159*> (19) Q ( T1, T2 ) Z    diag(T1)=( 0,0,1,1, 1-d, ..., 1-(N-5)*d=s, 0 )
160*>                        diag(T2) = ( 0, 1, 0, 1, ..., 1, 0 )
161*>
162*>                                                        N-5
163*> (20) Q ( T1, T2 ) Z    diag(T1)=( 0, 0, 1, 1, a, ..., a   =s, 0 )
164*>                        diag(T2) = ( 0, 1, 0, 1, ..., 1, 0, 0 )
165*>
166*> (21) Q ( T1, T2 ) Z    diag(T1)=( 0, 0, 1, r1, r2, ..., r(N-4), 0 )
167*>                        diag(T2) = ( 0, 1, 0, 1, ..., 1, 0, 0 )
168*>                        where r1,..., r(N-4) are random.
169*>
170*> (22) Q ( big*T1, small*T2 ) Z    diag(T1) = ( 0, 0, 1, ..., N-3, 0 )
171*>                                  diag(T2) = ( 0, 1, ..., 1, 0, 0 )
172*>
173*> (23) Q ( small*T1, big*T2 ) Z    diag(T1) = ( 0, 0, 1, ..., N-3, 0 )
174*>                                  diag(T2) = ( 0, 1, ..., 1, 0, 0 )
175*>
176*> (24) Q ( small*T1, small*T2 ) Z  diag(T1) = ( 0, 0, 1, ..., N-3, 0 )
177*>                                  diag(T2) = ( 0, 1, ..., 1, 0, 0 )
178*>
179*> (25) Q ( big*T1, big*T2 ) Z      diag(T1) = ( 0, 0, 1, ..., N-3, 0 )
180*>                                  diag(T2) = ( 0, 1, ..., 1, 0, 0 )
181*>
182*> (26) Q ( T1, T2 ) Z     where T1 and T2 are random upper-triangular
183*>                         matrices.
184*>
185*> \endverbatim
186*
187*  Arguments:
188*  ==========
189*
190*> \param[in] NSIZES
191*> \verbatim
192*>          NSIZES is INTEGER
193*>          The number of sizes of matrices to use.  If it is zero,
194*>          DDRGES does nothing.  NSIZES >= 0.
195*> \endverbatim
196*>
197*> \param[in] NN
198*> \verbatim
199*>          NN is INTEGER array, dimension (NSIZES)
200*>          An array containing the sizes to be used for the matrices.
201*>          Zero values will be skipped.  NN >= 0.
202*> \endverbatim
203*>
204*> \param[in] NTYPES
205*> \verbatim
206*>          NTYPES is INTEGER
207*>          The number of elements in DOTYPE.   If it is zero, DDRGES
208*>          does nothing.  It must be at least zero.  If it is MAXTYP+1
209*>          and NSIZES is 1, then an additional type, MAXTYP+1 is
210*>          defined, which is to use whatever matrix is in A on input.
211*>          This is only useful if DOTYPE(1:MAXTYP) is .FALSE. and
212*>          DOTYPE(MAXTYP+1) is .TRUE. .
213*> \endverbatim
214*>
215*> \param[in] DOTYPE
216*> \verbatim
217*>          DOTYPE is LOGICAL array, dimension (NTYPES)
218*>          If DOTYPE(j) is .TRUE., then for each size in NN a
219*>          matrix of that size and of type j will be generated.
220*>          If NTYPES is smaller than the maximum number of types
221*>          defined (PARAMETER MAXTYP), then types NTYPES+1 through
222*>          MAXTYP will not be generated. If NTYPES is larger
223*>          than MAXTYP, DOTYPE(MAXTYP+1) through DOTYPE(NTYPES)
224*>          will be ignored.
225*> \endverbatim
226*>
227*> \param[in,out] ISEED
228*> \verbatim
229*>          ISEED is INTEGER array, dimension (4)
230*>          On entry ISEED specifies the seed of the random number
231*>          generator. The array elements should be between 0 and 4095;
232*>          if not they will be reduced mod 4096. Also, ISEED(4) must
233*>          be odd.  The random number generator uses a linear
234*>          congruential sequence limited to small integers, and so
235*>          should produce machine independent random numbers. The
236*>          values of ISEED are changed on exit, and can be used in the
237*>          next call to DDRGES to continue the same random number
238*>          sequence.
239*> \endverbatim
240*>
241*> \param[in] THRESH
242*> \verbatim
243*>          THRESH is DOUBLE PRECISION
244*>          A test will count as "failed" if the "error", computed as
245*>          described above, exceeds THRESH.  Note that the error is
246*>          scaled to be O(1), so THRESH should be a reasonably small
247*>          multiple of 1, e.g., 10 or 100.  In particular, it should
248*>          not depend on the precision (single vs. double) or the size
249*>          of the matrix.  THRESH >= 0.
250*> \endverbatim
251*>
252*> \param[in] NOUNIT
253*> \verbatim
254*>          NOUNIT is INTEGER
255*>          The FORTRAN unit number for printing out error messages
256*>          (e.g., if a routine returns IINFO not equal to 0.)
257*> \endverbatim
258*>
259*> \param[in,out] A
260*> \verbatim
261*>          A is COMPLEX*16 array, dimension(LDA, max(NN))
262*>          Used to hold the original A matrix.  Used as input only
263*>          if NTYPES=MAXTYP+1, DOTYPE(1:MAXTYP)=.FALSE., and
264*>          DOTYPE(MAXTYP+1)=.TRUE.
265*> \endverbatim
266*>
267*> \param[in] LDA
268*> \verbatim
269*>          LDA is INTEGER
270*>          The leading dimension of A, B, S, and T.
271*>          It must be at least 1 and at least max( NN ).
272*> \endverbatim
273*>
274*> \param[in,out] B
275*> \verbatim
276*>          B is COMPLEX*16 array, dimension(LDA, max(NN))
277*>          Used to hold the original B matrix.  Used as input only
278*>          if NTYPES=MAXTYP+1, DOTYPE(1:MAXTYP)=.FALSE., and
279*>          DOTYPE(MAXTYP+1)=.TRUE.
280*> \endverbatim
281*>
282*> \param[out] S
283*> \verbatim
284*>          S is COMPLEX*16 array, dimension (LDA, max(NN))
285*>          The Schur form matrix computed from A by ZGGES.  On exit, S
286*>          contains the Schur form matrix corresponding to the matrix
287*>          in A.
288*> \endverbatim
289*>
290*> \param[out] T
291*> \verbatim
292*>          T is COMPLEX*16 array, dimension (LDA, max(NN))
293*>          The upper triangular matrix computed from B by ZGGES.
294*> \endverbatim
295*>
296*> \param[out] Q
297*> \verbatim
298*>          Q is COMPLEX*16 array, dimension (LDQ, max(NN))
299*>          The (left) orthogonal matrix computed by ZGGES.
300*> \endverbatim
301*>
302*> \param[in] LDQ
303*> \verbatim
304*>          LDQ is INTEGER
305*>          The leading dimension of Q and Z. It must
306*>          be at least 1 and at least max( NN ).
307*> \endverbatim
308*>
309*> \param[out] Z
310*> \verbatim
311*>          Z is COMPLEX*16 array, dimension( LDQ, max(NN) )
312*>          The (right) orthogonal matrix computed by ZGGES.
313*> \endverbatim
314*>
315*> \param[out] ALPHA
316*> \verbatim
317*>          ALPHA is COMPLEX*16 array, dimension (max(NN))
318*> \endverbatim
319*>
320*> \param[out] BETA
321*> \verbatim
322*>          BETA is COMPLEX*16 array, dimension (max(NN))
323*>
324*>          The generalized eigenvalues of (A,B) computed by ZGGES.
325*>          ALPHA(k) / BETA(k) is the k-th generalized eigenvalue of A
326*>          and B.
327*> \endverbatim
328*>
329*> \param[out] WORK
330*> \verbatim
331*>          WORK is COMPLEX*16 array, dimension (LWORK)
332*> \endverbatim
333*>
334*> \param[in] LWORK
335*> \verbatim
336*>          LWORK is INTEGER
337*>          The dimension of the array WORK.  LWORK >= 3*N*N.
338*> \endverbatim
339*>
340*> \param[out] RWORK
341*> \verbatim
342*>          RWORK is DOUBLE PRECISION array, dimension ( 8*N )
343*>          Real workspace.
344*> \endverbatim
345*>
346*> \param[out] RESULT
347*> \verbatim
348*>          RESULT is DOUBLE PRECISION array, dimension (15)
349*>          The values computed by the tests described above.
350*>          The values are currently limited to 1/ulp, to avoid overflow.
351*> \endverbatim
352*>
353*> \param[out] BWORK
354*> \verbatim
355*>          BWORK is LOGICAL array, dimension (N)
356*> \endverbatim
357*>
358*> \param[out] INFO
359*> \verbatim
360*>          INFO is INTEGER
361*>          = 0:  successful exit
362*>          < 0:  if INFO = -i, the i-th argument had an illegal value.
363*>          > 0:  A routine returned an error code.  INFO is the
364*>                absolute value of the INFO value returned.
365*> \endverbatim
366*
367*  Authors:
368*  ========
369*
370*> \author Univ. of Tennessee
371*> \author Univ. of California Berkeley
372*> \author Univ. of Colorado Denver
373*> \author NAG Ltd.
374*
375*> \date November 2011
376*
377*> \ingroup complex16_eig
378*
379*  =====================================================================
380      SUBROUTINE ZDRGES( NSIZES, NN, NTYPES, DOTYPE, ISEED, THRESH,
381     $                   NOUNIT, A, LDA, B, S, T, Q, LDQ, Z, ALPHA,
382     $                   BETA, WORK, LWORK, RWORK, RESULT, BWORK, INFO )
383*
384*  -- LAPACK test routine (version 3.4.0) --
385*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
386*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
387*     November 2011
388*
389*     .. Scalar Arguments ..
390      INTEGER            INFO, LDA, LDQ, LWORK, NOUNIT, NSIZES, NTYPES
391      DOUBLE PRECISION   THRESH
392*     ..
393*     .. Array Arguments ..
394      LOGICAL            BWORK( * ), DOTYPE( * )
395      INTEGER            ISEED( 4 ), NN( * )
396      DOUBLE PRECISION   RESULT( 13 ), RWORK( * )
397      COMPLEX*16         A( LDA, * ), ALPHA( * ), B( LDA, * ),
398     $                   BETA( * ), Q( LDQ, * ), S( LDA, * ),
399     $                   T( LDA, * ), WORK( * ), Z( LDQ, * )
400*     ..
401*
402*  =====================================================================
403*
404*     .. Parameters ..
405      DOUBLE PRECISION   ZERO, ONE
406      PARAMETER          ( ZERO = 0.0D+0, ONE = 1.0D+0 )
407      COMPLEX*16         CZERO, CONE
408      PARAMETER          ( CZERO = ( 0.0D+0, 0.0D+0 ),
409     $                   CONE = ( 1.0D+0, 0.0D+0 ) )
410      INTEGER            MAXTYP
411      PARAMETER          ( MAXTYP = 26 )
412*     ..
413*     .. Local Scalars ..
414      LOGICAL            BADNN, ILABAD
415      CHARACTER          SORT
416      INTEGER            I, IADD, IINFO, IN, ISORT, J, JC, JR, JSIZE,
417     $                   JTYPE, KNTEIG, MAXWRK, MINWRK, MTYPES, N, N1,
418     $                   NB, NERRS, NMATS, NMAX, NTEST, NTESTT, RSUB,
419     $                   SDIM
420      DOUBLE PRECISION   SAFMAX, SAFMIN, TEMP1, TEMP2, ULP, ULPINV
421      COMPLEX*16         CTEMP, X
422*     ..
423*     .. Local Arrays ..
424      LOGICAL            LASIGN( MAXTYP ), LBSIGN( MAXTYP )
425      INTEGER            IOLDSD( 4 ), KADD( 6 ), KAMAGN( MAXTYP ),
426     $                   KATYPE( MAXTYP ), KAZERO( MAXTYP ),
427     $                   KBMAGN( MAXTYP ), KBTYPE( MAXTYP ),
428     $                   KBZERO( MAXTYP ), KCLASS( MAXTYP ),
429     $                   KTRIAN( MAXTYP ), KZ1( 6 ), KZ2( 6 )
430      DOUBLE PRECISION   RMAGN( 0: 3 )
431*     ..
432*     .. External Functions ..
433      LOGICAL            ZLCTES
434      INTEGER            ILAENV
435      DOUBLE PRECISION   DLAMCH
436      COMPLEX*16         ZLARND
437      EXTERNAL           ZLCTES, ILAENV, DLAMCH, ZLARND
438*     ..
439*     .. External Subroutines ..
440      EXTERNAL           ALASVM, DLABAD, XERBLA, ZGET51, ZGET54, ZGGES,
441     $                   ZLACPY, ZLARFG, ZLASET, ZLATM4, ZUNM2R
442*     ..
443*     .. Intrinsic Functions ..
444      INTRINSIC          ABS, DBLE, DCONJG, DIMAG, MAX, MIN, SIGN
445*     ..
446*     .. Statement Functions ..
447      DOUBLE PRECISION   ABS1
448*     ..
449*     .. Statement Function definitions ..
450      ABS1( X ) = ABS( DBLE( X ) ) + ABS( DIMAG( X ) )
451*     ..
452*     .. Data statements ..
453      DATA               KCLASS / 15*1, 10*2, 1*3 /
454      DATA               KZ1 / 0, 1, 2, 1, 3, 3 /
455      DATA               KZ2 / 0, 0, 1, 2, 1, 1 /
456      DATA               KADD / 0, 0, 0, 0, 3, 2 /
457      DATA               KATYPE / 0, 1, 0, 1, 2, 3, 4, 1, 4, 4, 1, 1, 4,
458     $                   4, 4, 2, 4, 5, 8, 7, 9, 4*4, 0 /
459      DATA               KBTYPE / 0, 0, 1, 1, 2, -3, 1, 4, 1, 1, 4, 4,
460     $                   1, 1, -4, 2, -4, 8*8, 0 /
461      DATA               KAZERO / 6*1, 2, 1, 2*2, 2*1, 2*2, 3, 1, 3,
462     $                   4*5, 4*3, 1 /
463      DATA               KBZERO / 6*1, 1, 2, 2*1, 2*2, 2*1, 4, 1, 4,
464     $                   4*6, 4*4, 1 /
465      DATA               KAMAGN / 8*1, 2, 3, 2, 3, 2, 3, 7*1, 2, 3, 3,
466     $                   2, 1 /
467      DATA               KBMAGN / 8*1, 3, 2, 3, 2, 2, 3, 7*1, 3, 2, 3,
468     $                   2, 1 /
469      DATA               KTRIAN / 16*0, 10*1 /
470      DATA               LASIGN / 6*.FALSE., .TRUE., .FALSE., 2*.TRUE.,
471     $                   2*.FALSE., 3*.TRUE., .FALSE., .TRUE.,
472     $                   3*.FALSE., 5*.TRUE., .FALSE. /
473      DATA               LBSIGN / 7*.FALSE., .TRUE., 2*.FALSE.,
474     $                   2*.TRUE., 2*.FALSE., .TRUE., .FALSE., .TRUE.,
475     $                   9*.FALSE. /
476*     ..
477*     .. Executable Statements ..
478*
479*     Check for errors
480*
481      INFO = 0
482*
483      BADNN = .FALSE.
484      NMAX = 1
485      DO 10 J = 1, NSIZES
486         NMAX = MAX( NMAX, NN( J ) )
487         IF( NN( J ).LT.0 )
488     $      BADNN = .TRUE.
489   10 CONTINUE
490*
491      IF( NSIZES.LT.0 ) THEN
492         INFO = -1
493      ELSE IF( BADNN ) THEN
494         INFO = -2
495      ELSE IF( NTYPES.LT.0 ) THEN
496         INFO = -3
497      ELSE IF( THRESH.LT.ZERO ) THEN
498         INFO = -6
499      ELSE IF( LDA.LE.1 .OR. LDA.LT.NMAX ) THEN
500         INFO = -9
501      ELSE IF( LDQ.LE.1 .OR. LDQ.LT.NMAX ) THEN
502         INFO = -14
503      END IF
504*
505*     Compute workspace
506*      (Note: Comments in the code beginning "Workspace:" describe the
507*       minimal amount of workspace needed at that point in the code,
508*       as well as the preferred amount for good performance.
509*       NB refers to the optimal block size for the immediately
510*       following subroutine, as returned by ILAENV.
511*
512      MINWRK = 1
513      IF( INFO.EQ.0 .AND. LWORK.GE.1 ) THEN
514         MINWRK = 3*NMAX*NMAX
515         NB = MAX( 1, ILAENV( 1, 'ZGEQRF', ' ', NMAX, NMAX, -1, -1 ),
516     $        ILAENV( 1, 'ZUNMQR', 'LC', NMAX, NMAX, NMAX, -1 ),
517     $        ILAENV( 1, 'ZUNGQR', ' ', NMAX, NMAX, NMAX, -1 ) )
518         MAXWRK = MAX( NMAX+NMAX*NB, 3*NMAX*NMAX )
519         WORK( 1 ) = MAXWRK
520      END IF
521*
522      IF( LWORK.LT.MINWRK )
523     $   INFO = -19
524*
525      IF( INFO.NE.0 ) THEN
526         CALL XERBLA( 'ZDRGES', -INFO )
527         RETURN
528      END IF
529*
530*     Quick return if possible
531*
532      IF( NSIZES.EQ.0 .OR. NTYPES.EQ.0 )
533     $   RETURN
534*
535      ULP = DLAMCH( 'Precision' )
536      SAFMIN = DLAMCH( 'Safe minimum' )
537      SAFMIN = SAFMIN / ULP
538      SAFMAX = ONE / SAFMIN
539      CALL DLABAD( SAFMIN, SAFMAX )
540      ULPINV = ONE / ULP
541*
542*     The values RMAGN(2:3) depend on N, see below.
543*
544      RMAGN( 0 ) = ZERO
545      RMAGN( 1 ) = ONE
546*
547*     Loop over matrix sizes
548*
549      NTESTT = 0
550      NERRS = 0
551      NMATS = 0
552*
553      DO 190 JSIZE = 1, NSIZES
554         N = NN( JSIZE )
555         N1 = MAX( 1, N )
556         RMAGN( 2 ) = SAFMAX*ULP / DBLE( N1 )
557         RMAGN( 3 ) = SAFMIN*ULPINV*DBLE( N1 )
558*
559         IF( NSIZES.NE.1 ) THEN
560            MTYPES = MIN( MAXTYP, NTYPES )
561         ELSE
562            MTYPES = MIN( MAXTYP+1, NTYPES )
563         END IF
564*
565*        Loop over matrix types
566*
567         DO 180 JTYPE = 1, MTYPES
568            IF( .NOT.DOTYPE( JTYPE ) )
569     $         GO TO 180
570            NMATS = NMATS + 1
571            NTEST = 0
572*
573*           Save ISEED in case of an error.
574*
575            DO 20 J = 1, 4
576               IOLDSD( J ) = ISEED( J )
577   20       CONTINUE
578*
579*           Initialize RESULT
580*
581            DO 30 J = 1, 13
582               RESULT( J ) = ZERO
583   30       CONTINUE
584*
585*           Generate test matrices A and B
586*
587*           Description of control parameters:
588*
589*           KZLASS: =1 means w/o rotation, =2 means w/ rotation,
590*                   =3 means random.
591*           KATYPE: the "type" to be passed to ZLATM4 for computing A.
592*           KAZERO: the pattern of zeros on the diagonal for A:
593*                   =1: ( xxx ), =2: (0, xxx ) =3: ( 0, 0, xxx, 0 ),
594*                   =4: ( 0, xxx, 0, 0 ), =5: ( 0, 0, 1, xxx, 0 ),
595*                   =6: ( 0, 1, 0, xxx, 0 ).  (xxx means a string of
596*                   non-zero entries.)
597*           KAMAGN: the magnitude of the matrix: =0: zero, =1: O(1),
598*                   =2: large, =3: small.
599*           LASIGN: .TRUE. if the diagonal elements of A are to be
600*                   multiplied by a random magnitude 1 number.
601*           KBTYPE, KBZERO, KBMAGN, LBSIGN: the same, but for B.
602*           KTRIAN: =0: don't fill in the upper triangle, =1: do.
603*           KZ1, KZ2, KADD: used to implement KAZERO and KBZERO.
604*           RMAGN: used to implement KAMAGN and KBMAGN.
605*
606            IF( MTYPES.GT.MAXTYP )
607     $         GO TO 110
608            IINFO = 0
609            IF( KCLASS( JTYPE ).LT.3 ) THEN
610*
611*              Generate A (w/o rotation)
612*
613               IF( ABS( KATYPE( JTYPE ) ).EQ.3 ) THEN
614                  IN = 2*( ( N-1 ) / 2 ) + 1
615                  IF( IN.NE.N )
616     $               CALL ZLASET( 'Full', N, N, CZERO, CZERO, A, LDA )
617               ELSE
618                  IN = N
619               END IF
620               CALL ZLATM4( KATYPE( JTYPE ), IN, KZ1( KAZERO( JTYPE ) ),
621     $                      KZ2( KAZERO( JTYPE ) ), LASIGN( JTYPE ),
622     $                      RMAGN( KAMAGN( JTYPE ) ), ULP,
623     $                      RMAGN( KTRIAN( JTYPE )*KAMAGN( JTYPE ) ), 2,
624     $                      ISEED, A, LDA )
625               IADD = KADD( KAZERO( JTYPE ) )
626               IF( IADD.GT.0 .AND. IADD.LE.N )
627     $            A( IADD, IADD ) = RMAGN( KAMAGN( JTYPE ) )
628*
629*              Generate B (w/o rotation)
630*
631               IF( ABS( KBTYPE( JTYPE ) ).EQ.3 ) THEN
632                  IN = 2*( ( N-1 ) / 2 ) + 1
633                  IF( IN.NE.N )
634     $               CALL ZLASET( 'Full', N, N, CZERO, CZERO, B, LDA )
635               ELSE
636                  IN = N
637               END IF
638               CALL ZLATM4( KBTYPE( JTYPE ), IN, KZ1( KBZERO( JTYPE ) ),
639     $                      KZ2( KBZERO( JTYPE ) ), LBSIGN( JTYPE ),
640     $                      RMAGN( KBMAGN( JTYPE ) ), ONE,
641     $                      RMAGN( KTRIAN( JTYPE )*KBMAGN( JTYPE ) ), 2,
642     $                      ISEED, B, LDA )
643               IADD = KADD( KBZERO( JTYPE ) )
644               IF( IADD.NE.0 .AND. IADD.LE.N )
645     $            B( IADD, IADD ) = RMAGN( KBMAGN( JTYPE ) )
646*
647               IF( KCLASS( JTYPE ).EQ.2 .AND. N.GT.0 ) THEN
648*
649*                 Include rotations
650*
651*                 Generate Q, Z as Householder transformations times
652*                 a diagonal matrix.
653*
654                  DO 50 JC = 1, N - 1
655                     DO 40 JR = JC, N
656                        Q( JR, JC ) = ZLARND( 3, ISEED )
657                        Z( JR, JC ) = ZLARND( 3, ISEED )
658   40                CONTINUE
659                     CALL ZLARFG( N+1-JC, Q( JC, JC ), Q( JC+1, JC ), 1,
660     $                            WORK( JC ) )
661                     WORK( 2*N+JC ) = SIGN( ONE, DBLE( Q( JC, JC ) ) )
662                     Q( JC, JC ) = CONE
663                     CALL ZLARFG( N+1-JC, Z( JC, JC ), Z( JC+1, JC ), 1,
664     $                            WORK( N+JC ) )
665                     WORK( 3*N+JC ) = SIGN( ONE, DBLE( Z( JC, JC ) ) )
666                     Z( JC, JC ) = CONE
667   50             CONTINUE
668                  CTEMP = ZLARND( 3, ISEED )
669                  Q( N, N ) = CONE
670                  WORK( N ) = CZERO
671                  WORK( 3*N ) = CTEMP / ABS( CTEMP )
672                  CTEMP = ZLARND( 3, ISEED )
673                  Z( N, N ) = CONE
674                  WORK( 2*N ) = CZERO
675                  WORK( 4*N ) = CTEMP / ABS( CTEMP )
676*
677*                 Apply the diagonal matrices
678*
679                  DO 70 JC = 1, N
680                     DO 60 JR = 1, N
681                        A( JR, JC ) = WORK( 2*N+JR )*
682     $                                DCONJG( WORK( 3*N+JC ) )*
683     $                                A( JR, JC )
684                        B( JR, JC ) = WORK( 2*N+JR )*
685     $                                DCONJG( WORK( 3*N+JC ) )*
686     $                                B( JR, JC )
687   60                CONTINUE
688   70             CONTINUE
689                  CALL ZUNM2R( 'L', 'N', N, N, N-1, Q, LDQ, WORK, A,
690     $                         LDA, WORK( 2*N+1 ), IINFO )
691                  IF( IINFO.NE.0 )
692     $               GO TO 100
693                  CALL ZUNM2R( 'R', 'C', N, N, N-1, Z, LDQ, WORK( N+1 ),
694     $                         A, LDA, WORK( 2*N+1 ), IINFO )
695                  IF( IINFO.NE.0 )
696     $               GO TO 100
697                  CALL ZUNM2R( 'L', 'N', N, N, N-1, Q, LDQ, WORK, B,
698     $                         LDA, WORK( 2*N+1 ), IINFO )
699                  IF( IINFO.NE.0 )
700     $               GO TO 100
701                  CALL ZUNM2R( 'R', 'C', N, N, N-1, Z, LDQ, WORK( N+1 ),
702     $                         B, LDA, WORK( 2*N+1 ), IINFO )
703                  IF( IINFO.NE.0 )
704     $               GO TO 100
705               END IF
706            ELSE
707*
708*              Random matrices
709*
710               DO 90 JC = 1, N
711                  DO 80 JR = 1, N
712                     A( JR, JC ) = RMAGN( KAMAGN( JTYPE ) )*
713     $                             ZLARND( 4, ISEED )
714                     B( JR, JC ) = RMAGN( KBMAGN( JTYPE ) )*
715     $                             ZLARND( 4, ISEED )
716   80             CONTINUE
717   90          CONTINUE
718            END IF
719*
720  100       CONTINUE
721*
722            IF( IINFO.NE.0 ) THEN
723               WRITE( NOUNIT, FMT = 9999 )'Generator', IINFO, N, JTYPE,
724     $            IOLDSD
725               INFO = ABS( IINFO )
726               RETURN
727            END IF
728*
729  110       CONTINUE
730*
731            DO 120 I = 1, 13
732               RESULT( I ) = -ONE
733  120       CONTINUE
734*
735*           Test with and without sorting of eigenvalues
736*
737            DO 150 ISORT = 0, 1
738               IF( ISORT.EQ.0 ) THEN
739                  SORT = 'N'
740                  RSUB = 0
741               ELSE
742                  SORT = 'S'
743                  RSUB = 5
744               END IF
745*
746*              Call ZGGES to compute H, T, Q, Z, alpha, and beta.
747*
748               CALL ZLACPY( 'Full', N, N, A, LDA, S, LDA )
749               CALL ZLACPY( 'Full', N, N, B, LDA, T, LDA )
750               NTEST = 1 + RSUB + ISORT
751               RESULT( 1+RSUB+ISORT ) = ULPINV
752               CALL ZGGES( 'V', 'V', SORT, ZLCTES, N, S, LDA, T, LDA,
753     $                     SDIM, ALPHA, BETA, Q, LDQ, Z, LDQ, WORK,
754     $                     LWORK, RWORK, BWORK, IINFO )
755               IF( IINFO.NE.0 .AND. IINFO.NE.N+2 ) THEN
756                  RESULT( 1+RSUB+ISORT ) = ULPINV
757                  WRITE( NOUNIT, FMT = 9999 )'ZGGES', IINFO, N, JTYPE,
758     $               IOLDSD
759                  INFO = ABS( IINFO )
760                  GO TO 160
761               END IF
762*
763               NTEST = 4 + RSUB
764*
765*              Do tests 1--4 (or tests 7--9 when reordering )
766*
767               IF( ISORT.EQ.0 ) THEN
768                  CALL ZGET51( 1, N, A, LDA, S, LDA, Q, LDQ, Z, LDQ,
769     $                         WORK, RWORK, RESULT( 1 ) )
770                  CALL ZGET51( 1, N, B, LDA, T, LDA, Q, LDQ, Z, LDQ,
771     $                         WORK, RWORK, RESULT( 2 ) )
772               ELSE
773                  CALL ZGET54( N, A, LDA, B, LDA, S, LDA, T, LDA, Q,
774     $                         LDQ, Z, LDQ, WORK, RESULT( 2+RSUB ) )
775               END IF
776*
777               CALL ZGET51( 3, N, B, LDA, T, LDA, Q, LDQ, Q, LDQ, WORK,
778     $                      RWORK, RESULT( 3+RSUB ) )
779               CALL ZGET51( 3, N, B, LDA, T, LDA, Z, LDQ, Z, LDQ, WORK,
780     $                      RWORK, RESULT( 4+RSUB ) )
781*
782*              Do test 5 and 6 (or Tests 10 and 11 when reordering):
783*              check Schur form of A and compare eigenvalues with
784*              diagonals.
785*
786               NTEST = 6 + RSUB
787               TEMP1 = ZERO
788*
789               DO 130 J = 1, N
790                  ILABAD = .FALSE.
791                  TEMP2 = ( ABS1( ALPHA( J )-S( J, J ) ) /
792     $                    MAX( SAFMIN, ABS1( ALPHA( J ) ), ABS1( S( J,
793     $                    J ) ) )+ABS1( BETA( J )-T( J, J ) ) /
794     $                    MAX( SAFMIN, ABS1( BETA( J ) ), ABS1( T( J,
795     $                    J ) ) ) ) / ULP
796*
797                  IF( J.LT.N ) THEN
798                     IF( S( J+1, J ).NE.ZERO ) THEN
799                        ILABAD = .TRUE.
800                        RESULT( 5+RSUB ) = ULPINV
801                     END IF
802                  END IF
803                  IF( J.GT.1 ) THEN
804                     IF( S( J, J-1 ).NE.ZERO ) THEN
805                        ILABAD = .TRUE.
806                        RESULT( 5+RSUB ) = ULPINV
807                     END IF
808                  END IF
809                  TEMP1 = MAX( TEMP1, TEMP2 )
810                  IF( ILABAD ) THEN
811                     WRITE( NOUNIT, FMT = 9998 )J, N, JTYPE, IOLDSD
812                  END IF
813  130          CONTINUE
814               RESULT( 6+RSUB ) = TEMP1
815*
816               IF( ISORT.GE.1 ) THEN
817*
818*                 Do test 12
819*
820                  NTEST = 12
821                  RESULT( 12 ) = ZERO
822                  KNTEIG = 0
823                  DO 140 I = 1, N
824                     IF( ZLCTES( ALPHA( I ), BETA( I ) ) )
825     $                  KNTEIG = KNTEIG + 1
826  140             CONTINUE
827                  IF( SDIM.NE.KNTEIG )
828     $               RESULT( 13 ) = ULPINV
829               END IF
830*
831  150       CONTINUE
832*
833*           End of Loop -- Check for RESULT(j) > THRESH
834*
835  160       CONTINUE
836*
837            NTESTT = NTESTT + NTEST
838*
839*           Print out tests which fail.
840*
841            DO 170 JR = 1, NTEST
842               IF( RESULT( JR ).GE.THRESH ) THEN
843*
844*                 If this is the first test to fail,
845*                 print a header to the data file.
846*
847                  IF( NERRS.EQ.0 ) THEN
848                     WRITE( NOUNIT, FMT = 9997 )'ZGS'
849*
850*                    Matrix types
851*
852                     WRITE( NOUNIT, FMT = 9996 )
853                     WRITE( NOUNIT, FMT = 9995 )
854                     WRITE( NOUNIT, FMT = 9994 )'Unitary'
855*
856*                    Tests performed
857*
858                     WRITE( NOUNIT, FMT = 9993 )'unitary', '''',
859     $                  'transpose', ( '''', J = 1, 8 )
860*
861                  END IF
862                  NERRS = NERRS + 1
863                  IF( RESULT( JR ).LT.10000.0D0 ) THEN
864                     WRITE( NOUNIT, FMT = 9992 )N, JTYPE, IOLDSD, JR,
865     $                  RESULT( JR )
866                  ELSE
867                     WRITE( NOUNIT, FMT = 9991 )N, JTYPE, IOLDSD, JR,
868     $                  RESULT( JR )
869                  END IF
870               END IF
871  170       CONTINUE
872*
873  180    CONTINUE
874  190 CONTINUE
875*
876*     Summary
877*
878      CALL ALASVM( 'ZGS', NOUNIT, NERRS, NTESTT, 0 )
879*
880      WORK( 1 ) = MAXWRK
881*
882      RETURN
883*
884 9999 FORMAT( ' ZDRGES: ', A, ' returned INFO=', I6, '.', / 9X, 'N=',
885     $      I6, ', JTYPE=', I6, ', ISEED=(', 4( I4, ',' ), I5, ')' )
886*
887 9998 FORMAT( ' ZDRGES: S not in Schur form at eigenvalue ', I6, '.',
888     $      / 9X, 'N=', I6, ', JTYPE=', I6, ', ISEED=(', 3( I5, ',' ),
889     $      I5, ')' )
890*
891 9997 FORMAT( / 1X, A3, ' -- Complex Generalized Schur from problem ',
892     $      'driver' )
893*
894 9996 FORMAT( ' Matrix types (see ZDRGES for details): ' )
895*
896 9995 FORMAT( ' Special Matrices:', 23X,
897     $      '(J''=transposed Jordan block)',
898     $      / '   1=(0,0)  2=(I,0)  3=(0,I)  4=(I,I)  5=(J'',J'')  ',
899     $      '6=(diag(J'',I), diag(I,J''))', / ' Diagonal Matrices:  ( ',
900     $      'D=diag(0,1,2,...) )', / '   7=(D,I)   9=(large*D, small*I',
901     $      ')  11=(large*I, small*D)  13=(large*D, large*I)', /
902     $      '   8=(I,D)  10=(small*D, large*I)  12=(small*I, large*D) ',
903     $      ' 14=(small*D, small*I)', / '  15=(D, reversed D)' )
904 9994 FORMAT( ' Matrices Rotated by Random ', A, ' Matrices U, V:',
905     $      / '  16=Transposed Jordan Blocks             19=geometric ',
906     $      'alpha, beta=0,1', / '  17=arithm. alpha&beta             ',
907     $      '      20=arithmetic alpha, beta=0,1', / '  18=clustered ',
908     $      'alpha, beta=0,1            21=random alpha, beta=0,1',
909     $      / ' Large & Small Matrices:', / '  22=(large, small)   ',
910     $      '23=(small,large)    24=(small,small)    25=(large,large)',
911     $      / '  26=random O(1) matrices.' )
912*
913 9993 FORMAT( / ' Tests performed:  (S is Schur, T is triangular, ',
914     $      'Q and Z are ', A, ',', / 19X,
915     $      'l and r are the appropriate left and right', / 19X,
916     $      'eigenvectors, resp., a is alpha, b is beta, and', / 19X, A,
917     $      ' means ', A, '.)', / ' Without ordering: ',
918     $      / '  1 = | A - Q S Z', A,
919     $      ' | / ( |A| n ulp )      2 = | B - Q T Z', A,
920     $      ' | / ( |B| n ulp )', / '  3 = | I - QQ', A,
921     $      ' | / ( n ulp )             4 = | I - ZZ', A,
922     $      ' | / ( n ulp )', / '  5 = A is in Schur form S',
923     $      / '  6 = difference between (alpha,beta)',
924     $      ' and diagonals of (S,T)', / ' With ordering: ',
925     $      / '  7 = | (A,B) - Q (S,T) Z', A, ' | / ( |(A,B)| n ulp )',
926     $      / '  8 = | I - QQ', A,
927     $      ' | / ( n ulp )             9 = | I - ZZ', A,
928     $      ' | / ( n ulp )', / ' 10 = A is in Schur form S',
929     $      / ' 11 = difference between (alpha,beta) and diagonals',
930     $      ' of (S,T)', / ' 12 = SDIM is the correct number of ',
931     $      'selected eigenvalues', / )
932 9992 FORMAT( ' Matrix order=', I5, ', type=', I2, ', seed=',
933     $      4( I4, ',' ), ' result ', I2, ' is', 0P, F8.2 )
934 9991 FORMAT( ' Matrix order=', I5, ', type=', I2, ', seed=',
935     $      4( I4, ',' ), ' result ', I2, ' is', 1P, D10.3 )
936*
937*     End of ZDRGES
938*
939      END
940