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 threshold 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*> \ingroup complex16_eig
376*
377*  =====================================================================
378      SUBROUTINE ZDRGES( NSIZES, NN, NTYPES, DOTYPE, ISEED, THRESH,
379     $                   NOUNIT, A, LDA, B, S, T, Q, LDQ, Z, ALPHA,
380     $                   BETA, WORK, LWORK, RWORK, RESULT, BWORK, INFO )
381*
382*  -- LAPACK test routine --
383*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
384*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
385*
386*     .. Scalar Arguments ..
387      INTEGER            INFO, LDA, LDQ, LWORK, NOUNIT, NSIZES, NTYPES
388      DOUBLE PRECISION   THRESH
389*     ..
390*     .. Array Arguments ..
391      LOGICAL            BWORK( * ), DOTYPE( * )
392      INTEGER            ISEED( 4 ), NN( * )
393      DOUBLE PRECISION   RESULT( 13 ), RWORK( * )
394      COMPLEX*16         A( LDA, * ), ALPHA( * ), B( LDA, * ),
395     $                   BETA( * ), Q( LDQ, * ), S( LDA, * ),
396     $                   T( LDA, * ), WORK( * ), Z( LDQ, * )
397*     ..
398*
399*  =====================================================================
400*
401*     .. Parameters ..
402      DOUBLE PRECISION   ZERO, ONE
403      PARAMETER          ( ZERO = 0.0D+0, ONE = 1.0D+0 )
404      COMPLEX*16         CZERO, CONE
405      PARAMETER          ( CZERO = ( 0.0D+0, 0.0D+0 ),
406     $                   CONE = ( 1.0D+0, 0.0D+0 ) )
407      INTEGER            MAXTYP
408      PARAMETER          ( MAXTYP = 26 )
409*     ..
410*     .. Local Scalars ..
411      LOGICAL            BADNN, ILABAD
412      CHARACTER          SORT
413      INTEGER            I, IADD, IINFO, IN, ISORT, J, JC, JR, JSIZE,
414     $                   JTYPE, KNTEIG, MAXWRK, MINWRK, MTYPES, N, N1,
415     $                   NB, NERRS, NMATS, NMAX, NTEST, NTESTT, RSUB,
416     $                   SDIM
417      DOUBLE PRECISION   SAFMAX, SAFMIN, TEMP1, TEMP2, ULP, ULPINV
418      COMPLEX*16         CTEMP, X
419*     ..
420*     .. Local Arrays ..
421      LOGICAL            LASIGN( MAXTYP ), LBSIGN( MAXTYP )
422      INTEGER            IOLDSD( 4 ), KADD( 6 ), KAMAGN( MAXTYP ),
423     $                   KATYPE( MAXTYP ), KAZERO( MAXTYP ),
424     $                   KBMAGN( MAXTYP ), KBTYPE( MAXTYP ),
425     $                   KBZERO( MAXTYP ), KCLASS( MAXTYP ),
426     $                   KTRIAN( MAXTYP ), KZ1( 6 ), KZ2( 6 )
427      DOUBLE PRECISION   RMAGN( 0: 3 )
428*     ..
429*     .. External Functions ..
430      LOGICAL            ZLCTES
431      INTEGER            ILAENV
432      DOUBLE PRECISION   DLAMCH
433      COMPLEX*16         ZLARND
434      EXTERNAL           ZLCTES, ILAENV, DLAMCH, ZLARND
435*     ..
436*     .. External Subroutines ..
437      EXTERNAL           ALASVM, DLABAD, XERBLA, ZGET51, ZGET54, ZGGES,
438     $                   ZLACPY, ZLARFG, ZLASET, ZLATM4, ZUNM2R
439*     ..
440*     .. Intrinsic Functions ..
441      INTRINSIC          ABS, DBLE, DCONJG, DIMAG, MAX, MIN, SIGN
442*     ..
443*     .. Statement Functions ..
444      DOUBLE PRECISION   ABS1
445*     ..
446*     .. Statement Function definitions ..
447      ABS1( X ) = ABS( DBLE( X ) ) + ABS( DIMAG( X ) )
448*     ..
449*     .. Data statements ..
450      DATA               KCLASS / 15*1, 10*2, 1*3 /
451      DATA               KZ1 / 0, 1, 2, 1, 3, 3 /
452      DATA               KZ2 / 0, 0, 1, 2, 1, 1 /
453      DATA               KADD / 0, 0, 0, 0, 3, 2 /
454      DATA               KATYPE / 0, 1, 0, 1, 2, 3, 4, 1, 4, 4, 1, 1, 4,
455     $                   4, 4, 2, 4, 5, 8, 7, 9, 4*4, 0 /
456      DATA               KBTYPE / 0, 0, 1, 1, 2, -3, 1, 4, 1, 1, 4, 4,
457     $                   1, 1, -4, 2, -4, 8*8, 0 /
458      DATA               KAZERO / 6*1, 2, 1, 2*2, 2*1, 2*2, 3, 1, 3,
459     $                   4*5, 4*3, 1 /
460      DATA               KBZERO / 6*1, 1, 2, 2*1, 2*2, 2*1, 4, 1, 4,
461     $                   4*6, 4*4, 1 /
462      DATA               KAMAGN / 8*1, 2, 3, 2, 3, 2, 3, 7*1, 2, 3, 3,
463     $                   2, 1 /
464      DATA               KBMAGN / 8*1, 3, 2, 3, 2, 2, 3, 7*1, 3, 2, 3,
465     $                   2, 1 /
466      DATA               KTRIAN / 16*0, 10*1 /
467      DATA               LASIGN / 6*.FALSE., .TRUE., .FALSE., 2*.TRUE.,
468     $                   2*.FALSE., 3*.TRUE., .FALSE., .TRUE.,
469     $                   3*.FALSE., 5*.TRUE., .FALSE. /
470      DATA               LBSIGN / 7*.FALSE., .TRUE., 2*.FALSE.,
471     $                   2*.TRUE., 2*.FALSE., .TRUE., .FALSE., .TRUE.,
472     $                   9*.FALSE. /
473*     ..
474*     .. Executable Statements ..
475*
476*     Check for errors
477*
478      INFO = 0
479*
480      BADNN = .FALSE.
481      NMAX = 1
482      DO 10 J = 1, NSIZES
483         NMAX = MAX( NMAX, NN( J ) )
484         IF( NN( J ).LT.0 )
485     $      BADNN = .TRUE.
486   10 CONTINUE
487*
488      IF( NSIZES.LT.0 ) THEN
489         INFO = -1
490      ELSE IF( BADNN ) THEN
491         INFO = -2
492      ELSE IF( NTYPES.LT.0 ) THEN
493         INFO = -3
494      ELSE IF( THRESH.LT.ZERO ) THEN
495         INFO = -6
496      ELSE IF( LDA.LE.1 .OR. LDA.LT.NMAX ) THEN
497         INFO = -9
498      ELSE IF( LDQ.LE.1 .OR. LDQ.LT.NMAX ) THEN
499         INFO = -14
500      END IF
501*
502*     Compute workspace
503*      (Note: Comments in the code beginning "Workspace:" describe the
504*       minimal amount of workspace needed at that point in the code,
505*       as well as the preferred amount for good performance.
506*       NB refers to the optimal block size for the immediately
507*       following subroutine, as returned by ILAENV.
508*
509      MINWRK = 1
510      IF( INFO.EQ.0 .AND. LWORK.GE.1 ) THEN
511         MINWRK = 3*NMAX*NMAX
512         NB = MAX( 1, ILAENV( 1, 'ZGEQRF', ' ', NMAX, NMAX, -1, -1 ),
513     $        ILAENV( 1, 'ZUNMQR', 'LC', NMAX, NMAX, NMAX, -1 ),
514     $        ILAENV( 1, 'ZUNGQR', ' ', NMAX, NMAX, NMAX, -1 ) )
515         MAXWRK = MAX( NMAX+NMAX*NB, 3*NMAX*NMAX )
516         WORK( 1 ) = MAXWRK
517      END IF
518*
519      IF( LWORK.LT.MINWRK )
520     $   INFO = -19
521*
522      IF( INFO.NE.0 ) THEN
523         CALL XERBLA( 'ZDRGES', -INFO )
524         RETURN
525      END IF
526*
527*     Quick return if possible
528*
529      IF( NSIZES.EQ.0 .OR. NTYPES.EQ.0 )
530     $   RETURN
531*
532      ULP = DLAMCH( 'Precision' )
533      SAFMIN = DLAMCH( 'Safe minimum' )
534      SAFMIN = SAFMIN / ULP
535      SAFMAX = ONE / SAFMIN
536      CALL DLABAD( SAFMIN, SAFMAX )
537      ULPINV = ONE / ULP
538*
539*     The values RMAGN(2:3) depend on N, see below.
540*
541      RMAGN( 0 ) = ZERO
542      RMAGN( 1 ) = ONE
543*
544*     Loop over matrix sizes
545*
546      NTESTT = 0
547      NERRS = 0
548      NMATS = 0
549*
550      DO 190 JSIZE = 1, NSIZES
551         N = NN( JSIZE )
552         N1 = MAX( 1, N )
553         RMAGN( 2 ) = SAFMAX*ULP / DBLE( N1 )
554         RMAGN( 3 ) = SAFMIN*ULPINV*DBLE( N1 )
555*
556         IF( NSIZES.NE.1 ) THEN
557            MTYPES = MIN( MAXTYP, NTYPES )
558         ELSE
559            MTYPES = MIN( MAXTYP+1, NTYPES )
560         END IF
561*
562*        Loop over matrix types
563*
564         DO 180 JTYPE = 1, MTYPES
565            IF( .NOT.DOTYPE( JTYPE ) )
566     $         GO TO 180
567            NMATS = NMATS + 1
568            NTEST = 0
569*
570*           Save ISEED in case of an error.
571*
572            DO 20 J = 1, 4
573               IOLDSD( J ) = ISEED( J )
574   20       CONTINUE
575*
576*           Initialize RESULT
577*
578            DO 30 J = 1, 13
579               RESULT( J ) = ZERO
580   30       CONTINUE
581*
582*           Generate test matrices A and B
583*
584*           Description of control parameters:
585*
586*           KZLASS: =1 means w/o rotation, =2 means w/ rotation,
587*                   =3 means random.
588*           KATYPE: the "type" to be passed to ZLATM4 for computing A.
589*           KAZERO: the pattern of zeros on the diagonal for A:
590*                   =1: ( xxx ), =2: (0, xxx ) =3: ( 0, 0, xxx, 0 ),
591*                   =4: ( 0, xxx, 0, 0 ), =5: ( 0, 0, 1, xxx, 0 ),
592*                   =6: ( 0, 1, 0, xxx, 0 ).  (xxx means a string of
593*                   non-zero entries.)
594*           KAMAGN: the magnitude of the matrix: =0: zero, =1: O(1),
595*                   =2: large, =3: small.
596*           LASIGN: .TRUE. if the diagonal elements of A are to be
597*                   multiplied by a random magnitude 1 number.
598*           KBTYPE, KBZERO, KBMAGN, LBSIGN: the same, but for B.
599*           KTRIAN: =0: don't fill in the upper triangle, =1: do.
600*           KZ1, KZ2, KADD: used to implement KAZERO and KBZERO.
601*           RMAGN: used to implement KAMAGN and KBMAGN.
602*
603            IF( MTYPES.GT.MAXTYP )
604     $         GO TO 110
605            IINFO = 0
606            IF( KCLASS( JTYPE ).LT.3 ) THEN
607*
608*              Generate A (w/o rotation)
609*
610               IF( ABS( KATYPE( JTYPE ) ).EQ.3 ) THEN
611                  IN = 2*( ( N-1 ) / 2 ) + 1
612                  IF( IN.NE.N )
613     $               CALL ZLASET( 'Full', N, N, CZERO, CZERO, A, LDA )
614               ELSE
615                  IN = N
616               END IF
617               CALL ZLATM4( KATYPE( JTYPE ), IN, KZ1( KAZERO( JTYPE ) ),
618     $                      KZ2( KAZERO( JTYPE ) ), LASIGN( JTYPE ),
619     $                      RMAGN( KAMAGN( JTYPE ) ), ULP,
620     $                      RMAGN( KTRIAN( JTYPE )*KAMAGN( JTYPE ) ), 2,
621     $                      ISEED, A, LDA )
622               IADD = KADD( KAZERO( JTYPE ) )
623               IF( IADD.GT.0 .AND. IADD.LE.N )
624     $            A( IADD, IADD ) = RMAGN( KAMAGN( JTYPE ) )
625*
626*              Generate B (w/o rotation)
627*
628               IF( ABS( KBTYPE( JTYPE ) ).EQ.3 ) THEN
629                  IN = 2*( ( N-1 ) / 2 ) + 1
630                  IF( IN.NE.N )
631     $               CALL ZLASET( 'Full', N, N, CZERO, CZERO, B, LDA )
632               ELSE
633                  IN = N
634               END IF
635               CALL ZLATM4( KBTYPE( JTYPE ), IN, KZ1( KBZERO( JTYPE ) ),
636     $                      KZ2( KBZERO( JTYPE ) ), LBSIGN( JTYPE ),
637     $                      RMAGN( KBMAGN( JTYPE ) ), ONE,
638     $                      RMAGN( KTRIAN( JTYPE )*KBMAGN( JTYPE ) ), 2,
639     $                      ISEED, B, LDA )
640               IADD = KADD( KBZERO( JTYPE ) )
641               IF( IADD.NE.0 .AND. IADD.LE.N )
642     $            B( IADD, IADD ) = RMAGN( KBMAGN( JTYPE ) )
643*
644               IF( KCLASS( JTYPE ).EQ.2 .AND. N.GT.0 ) THEN
645*
646*                 Include rotations
647*
648*                 Generate Q, Z as Householder transformations times
649*                 a diagonal matrix.
650*
651                  DO 50 JC = 1, N - 1
652                     DO 40 JR = JC, N
653                        Q( JR, JC ) = ZLARND( 3, ISEED )
654                        Z( JR, JC ) = ZLARND( 3, ISEED )
655   40                CONTINUE
656                     CALL ZLARFG( N+1-JC, Q( JC, JC ), Q( JC+1, JC ), 1,
657     $                            WORK( JC ) )
658                     WORK( 2*N+JC ) = SIGN( ONE, DBLE( Q( JC, JC ) ) )
659                     Q( JC, JC ) = CONE
660                     CALL ZLARFG( N+1-JC, Z( JC, JC ), Z( JC+1, JC ), 1,
661     $                            WORK( N+JC ) )
662                     WORK( 3*N+JC ) = SIGN( ONE, DBLE( Z( JC, JC ) ) )
663                     Z( JC, JC ) = CONE
664   50             CONTINUE
665                  CTEMP = ZLARND( 3, ISEED )
666                  Q( N, N ) = CONE
667                  WORK( N ) = CZERO
668                  WORK( 3*N ) = CTEMP / ABS( CTEMP )
669                  CTEMP = ZLARND( 3, ISEED )
670                  Z( N, N ) = CONE
671                  WORK( 2*N ) = CZERO
672                  WORK( 4*N ) = CTEMP / ABS( CTEMP )
673*
674*                 Apply the diagonal matrices
675*
676                  DO 70 JC = 1, N
677                     DO 60 JR = 1, N
678                        A( JR, JC ) = WORK( 2*N+JR )*
679     $                                DCONJG( WORK( 3*N+JC ) )*
680     $                                A( JR, JC )
681                        B( JR, JC ) = WORK( 2*N+JR )*
682     $                                DCONJG( WORK( 3*N+JC ) )*
683     $                                B( JR, JC )
684   60                CONTINUE
685   70             CONTINUE
686                  CALL ZUNM2R( 'L', 'N', N, N, N-1, Q, LDQ, WORK, A,
687     $                         LDA, WORK( 2*N+1 ), IINFO )
688                  IF( IINFO.NE.0 )
689     $               GO TO 100
690                  CALL ZUNM2R( 'R', 'C', N, N, N-1, Z, LDQ, WORK( N+1 ),
691     $                         A, LDA, WORK( 2*N+1 ), IINFO )
692                  IF( IINFO.NE.0 )
693     $               GO TO 100
694                  CALL ZUNM2R( 'L', 'N', N, N, N-1, Q, LDQ, WORK, B,
695     $                         LDA, WORK( 2*N+1 ), IINFO )
696                  IF( IINFO.NE.0 )
697     $               GO TO 100
698                  CALL ZUNM2R( 'R', 'C', N, N, N-1, Z, LDQ, WORK( N+1 ),
699     $                         B, LDA, WORK( 2*N+1 ), IINFO )
700                  IF( IINFO.NE.0 )
701     $               GO TO 100
702               END IF
703            ELSE
704*
705*              Random matrices
706*
707               DO 90 JC = 1, N
708                  DO 80 JR = 1, N
709                     A( JR, JC ) = RMAGN( KAMAGN( JTYPE ) )*
710     $                             ZLARND( 4, ISEED )
711                     B( JR, JC ) = RMAGN( KBMAGN( JTYPE ) )*
712     $                             ZLARND( 4, ISEED )
713   80             CONTINUE
714   90          CONTINUE
715            END IF
716*
717  100       CONTINUE
718*
719            IF( IINFO.NE.0 ) THEN
720               WRITE( NOUNIT, FMT = 9999 )'Generator', IINFO, N, JTYPE,
721     $            IOLDSD
722               INFO = ABS( IINFO )
723               RETURN
724            END IF
725*
726  110       CONTINUE
727*
728            DO 120 I = 1, 13
729               RESULT( I ) = -ONE
730  120       CONTINUE
731*
732*           Test with and without sorting of eigenvalues
733*
734            DO 150 ISORT = 0, 1
735               IF( ISORT.EQ.0 ) THEN
736                  SORT = 'N'
737                  RSUB = 0
738               ELSE
739                  SORT = 'S'
740                  RSUB = 5
741               END IF
742*
743*              Call ZGGES to compute H, T, Q, Z, alpha, and beta.
744*
745               CALL ZLACPY( 'Full', N, N, A, LDA, S, LDA )
746               CALL ZLACPY( 'Full', N, N, B, LDA, T, LDA )
747               NTEST = 1 + RSUB + ISORT
748               RESULT( 1+RSUB+ISORT ) = ULPINV
749               CALL ZGGES( 'V', 'V', SORT, ZLCTES, N, S, LDA, T, LDA,
750     $                     SDIM, ALPHA, BETA, Q, LDQ, Z, LDQ, WORK,
751     $                     LWORK, RWORK, BWORK, IINFO )
752               IF( IINFO.NE.0 .AND. IINFO.NE.N+2 ) THEN
753                  RESULT( 1+RSUB+ISORT ) = ULPINV
754                  WRITE( NOUNIT, FMT = 9999 )'ZGGES', IINFO, N, JTYPE,
755     $               IOLDSD
756                  INFO = ABS( IINFO )
757                  GO TO 160
758               END IF
759*
760               NTEST = 4 + RSUB
761*
762*              Do tests 1--4 (or tests 7--9 when reordering )
763*
764               IF( ISORT.EQ.0 ) THEN
765                  CALL ZGET51( 1, N, A, LDA, S, LDA, Q, LDQ, Z, LDQ,
766     $                         WORK, RWORK, RESULT( 1 ) )
767                  CALL ZGET51( 1, N, B, LDA, T, LDA, Q, LDQ, Z, LDQ,
768     $                         WORK, RWORK, RESULT( 2 ) )
769               ELSE
770                  CALL ZGET54( N, A, LDA, B, LDA, S, LDA, T, LDA, Q,
771     $                         LDQ, Z, LDQ, WORK, RESULT( 2+RSUB ) )
772               END IF
773*
774               CALL ZGET51( 3, N, B, LDA, T, LDA, Q, LDQ, Q, LDQ, WORK,
775     $                      RWORK, RESULT( 3+RSUB ) )
776               CALL ZGET51( 3, N, B, LDA, T, LDA, Z, LDQ, Z, LDQ, WORK,
777     $                      RWORK, RESULT( 4+RSUB ) )
778*
779*              Do test 5 and 6 (or Tests 10 and 11 when reordering):
780*              check Schur form of A and compare eigenvalues with
781*              diagonals.
782*
783               NTEST = 6 + RSUB
784               TEMP1 = ZERO
785*
786               DO 130 J = 1, N
787                  ILABAD = .FALSE.
788                  TEMP2 = ( ABS1( ALPHA( J )-S( J, J ) ) /
789     $                    MAX( SAFMIN, ABS1( ALPHA( J ) ), ABS1( S( J,
790     $                    J ) ) )+ABS1( BETA( J )-T( J, J ) ) /
791     $                    MAX( SAFMIN, ABS1( BETA( J ) ), ABS1( T( J,
792     $                    J ) ) ) ) / ULP
793*
794                  IF( J.LT.N ) THEN
795                     IF( S( J+1, J ).NE.ZERO ) THEN
796                        ILABAD = .TRUE.
797                        RESULT( 5+RSUB ) = ULPINV
798                     END IF
799                  END IF
800                  IF( J.GT.1 ) THEN
801                     IF( S( J, J-1 ).NE.ZERO ) THEN
802                        ILABAD = .TRUE.
803                        RESULT( 5+RSUB ) = ULPINV
804                     END IF
805                  END IF
806                  TEMP1 = MAX( TEMP1, TEMP2 )
807                  IF( ILABAD ) THEN
808                     WRITE( NOUNIT, FMT = 9998 )J, N, JTYPE, IOLDSD
809                  END IF
810  130          CONTINUE
811               RESULT( 6+RSUB ) = TEMP1
812*
813               IF( ISORT.GE.1 ) THEN
814*
815*                 Do test 12
816*
817                  NTEST = 12
818                  RESULT( 12 ) = ZERO
819                  KNTEIG = 0
820                  DO 140 I = 1, N
821                     IF( ZLCTES( ALPHA( I ), BETA( I ) ) )
822     $                  KNTEIG = KNTEIG + 1
823  140             CONTINUE
824                  IF( SDIM.NE.KNTEIG )
825     $               RESULT( 13 ) = ULPINV
826               END IF
827*
828  150       CONTINUE
829*
830*           End of Loop -- Check for RESULT(j) > THRESH
831*
832  160       CONTINUE
833*
834            NTESTT = NTESTT + NTEST
835*
836*           Print out tests which fail.
837*
838            DO 170 JR = 1, NTEST
839               IF( RESULT( JR ).GE.THRESH ) THEN
840*
841*                 If this is the first test to fail,
842*                 print a header to the data file.
843*
844                  IF( NERRS.EQ.0 ) THEN
845                     WRITE( NOUNIT, FMT = 9997 )'ZGS'
846*
847*                    Matrix types
848*
849                     WRITE( NOUNIT, FMT = 9996 )
850                     WRITE( NOUNIT, FMT = 9995 )
851                     WRITE( NOUNIT, FMT = 9994 )'Unitary'
852*
853*                    Tests performed
854*
855                     WRITE( NOUNIT, FMT = 9993 )'unitary', '''',
856     $                  'transpose', ( '''', J = 1, 8 )
857*
858                  END IF
859                  NERRS = NERRS + 1
860                  IF( RESULT( JR ).LT.10000.0D0 ) THEN
861                     WRITE( NOUNIT, FMT = 9992 )N, JTYPE, IOLDSD, JR,
862     $                  RESULT( JR )
863                  ELSE
864                     WRITE( NOUNIT, FMT = 9991 )N, JTYPE, IOLDSD, JR,
865     $                  RESULT( JR )
866                  END IF
867               END IF
868  170       CONTINUE
869*
870  180    CONTINUE
871  190 CONTINUE
872*
873*     Summary
874*
875      CALL ALASVM( 'ZGS', NOUNIT, NERRS, NTESTT, 0 )
876*
877      WORK( 1 ) = MAXWRK
878*
879      RETURN
880*
881 9999 FORMAT( ' ZDRGES: ', A, ' returned INFO=', I6, '.', / 9X, 'N=',
882     $      I6, ', JTYPE=', I6, ', ISEED=(', 4( I4, ',' ), I5, ')' )
883*
884 9998 FORMAT( ' ZDRGES: S not in Schur form at eigenvalue ', I6, '.',
885     $      / 9X, 'N=', I6, ', JTYPE=', I6, ', ISEED=(', 3( I5, ',' ),
886     $      I5, ')' )
887*
888 9997 FORMAT( / 1X, A3, ' -- Complex Generalized Schur from problem ',
889     $      'driver' )
890*
891 9996 FORMAT( ' Matrix types (see ZDRGES for details): ' )
892*
893 9995 FORMAT( ' Special Matrices:', 23X,
894     $      '(J''=transposed Jordan block)',
895     $      / '   1=(0,0)  2=(I,0)  3=(0,I)  4=(I,I)  5=(J'',J'')  ',
896     $      '6=(diag(J'',I), diag(I,J''))', / ' Diagonal Matrices:  ( ',
897     $      'D=diag(0,1,2,...) )', / '   7=(D,I)   9=(large*D, small*I',
898     $      ')  11=(large*I, small*D)  13=(large*D, large*I)', /
899     $      '   8=(I,D)  10=(small*D, large*I)  12=(small*I, large*D) ',
900     $      ' 14=(small*D, small*I)', / '  15=(D, reversed D)' )
901 9994 FORMAT( ' Matrices Rotated by Random ', A, ' Matrices U, V:',
902     $      / '  16=Transposed Jordan Blocks             19=geometric ',
903     $      'alpha, beta=0,1', / '  17=arithm. alpha&beta             ',
904     $      '      20=arithmetic alpha, beta=0,1', / '  18=clustered ',
905     $      'alpha, beta=0,1            21=random alpha, beta=0,1',
906     $      / ' Large & Small Matrices:', / '  22=(large, small)   ',
907     $      '23=(small,large)    24=(small,small)    25=(large,large)',
908     $      / '  26=random O(1) matrices.' )
909*
910 9993 FORMAT( / ' Tests performed:  (S is Schur, T is triangular, ',
911     $      'Q and Z are ', A, ',', / 19X,
912     $      'l and r are the appropriate left and right', / 19X,
913     $      'eigenvectors, resp., a is alpha, b is beta, and', / 19X, A,
914     $      ' means ', A, '.)', / ' Without ordering: ',
915     $      / '  1 = | A - Q S Z', A,
916     $      ' | / ( |A| n ulp )      2 = | B - Q T Z', A,
917     $      ' | / ( |B| n ulp )', / '  3 = | I - QQ', A,
918     $      ' | / ( n ulp )             4 = | I - ZZ', A,
919     $      ' | / ( n ulp )', / '  5 = A is in Schur form S',
920     $      / '  6 = difference between (alpha,beta)',
921     $      ' and diagonals of (S,T)', / ' With ordering: ',
922     $      / '  7 = | (A,B) - Q (S,T) Z', A, ' | / ( |(A,B)| n ulp )',
923     $      / '  8 = | I - QQ', A,
924     $      ' | / ( n ulp )             9 = | I - ZZ', A,
925     $      ' | / ( n ulp )', / ' 10 = A is in Schur form S',
926     $      / ' 11 = difference between (alpha,beta) and diagonals',
927     $      ' of (S,T)', / ' 12 = SDIM is the correct number of ',
928     $      'selected eigenvalues', / )
929 9992 FORMAT( ' Matrix order=', I5, ', type=', I2, ', seed=',
930     $      4( I4, ',' ), ' result ', I2, ' is', 0P, F8.2 )
931 9991 FORMAT( ' Matrix order=', I5, ', type=', I2, ', seed=',
932     $      4( I4, ',' ), ' result ', I2, ' is', 1P, D10.3 )
933*
934*     End of ZDRGES
935*
936      END
937