1*> \brief \b SDRGES3
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 SDRGES3( NSIZES, NN, NTYPES, DOTYPE, ISEED, THRESH,
12*                           NOUNIT, A, LDA, B, S, T, Q, LDQ, Z, ALPHAR,
13*                           ALPHAI, BETA, WORK, LWORK, RESULT, BWORK,
14*                           INFO )
15*
16*       .. Scalar Arguments ..
17*       INTEGER            INFO, LDA, LDQ, LWORK, NOUNIT, NSIZES, NTYPES
18*       REAL               THRESH
19*       ..
20*       .. Array Arguments ..
21*       LOGICAL            BWORK( * ), DOTYPE( * )
22*       INTEGER            ISEED( 4 ), NN( * )
23*       REAL               A( LDA, * ), ALPHAI( * ), ALPHAR( * ),
24*      $                   B( LDA, * ), BETA( * ), Q( LDQ, * ),
25*      $                   RESULT( 13 ), S( LDA, * ), T( LDA, * ),
26*      $                   WORK( * ), Z( LDQ, * )
27*       ..
28*
29*
30*> \par Purpose:
31*  =============
32*>
33*> \verbatim
34*>
35*> SDRGES3 checks the nonsymmetric generalized eigenvalue (Schur form)
36*> problem driver SGGES3.
37*>
38*> SGGES3 factors A and B as Q S Z'  and Q T Z' , where ' means
39*> transpose, T is upper triangular, S is in generalized Schur form
40*> (block upper triangular, with 1x1 and 2x2 blocks on the diagonal,
41*> the 2x2 blocks corresponding to complex conjugate pairs of
42*> generalized eigenvalues), and Q and Z are orthogonal. It also
43*> computes the generalized eigenvalues (alpha(j),beta(j)), j=1,...,n,
44*> Thus, w(j) = alpha(j)/beta(j) is a root of the characteristic
45*> equation
46*>                 det( A - w(j) B ) = 0
47*> Optionally it also reorder the eigenvalues so that a selected
48*> cluster of eigenvalues appears in the leading diagonal block of the
49*> Schur forms.
50*>
51*> When SDRGES3 is called, a number of matrix "sizes" ("N's") and a
52*> number of matrix "TYPES" are specified.  For each size ("N")
53*> and each TYPE of matrix, a pair of matrices (A, B) will be generated
54*> and used for testing. For each matrix pair, the following 13 tests
55*> will be performed and compared with the threshold THRESH except
56*> the tests (5), (11) and (13).
57*>
58*>
59*> (1)   | A - Q S Z' | / ( |A| n ulp ) (no sorting of eigenvalues)
60*>
61*>
62*> (2)   | B - Q T Z' | / ( |B| n ulp ) (no sorting of eigenvalues)
63*>
64*>
65*> (3)   | I - QQ' | / ( n ulp ) (no sorting of eigenvalues)
66*>
67*>
68*> (4)   | I - ZZ' | / ( n ulp ) (no sorting of eigenvalues)
69*>
70*> (5)   if A is in Schur form (i.e. quasi-triangular form)
71*>       (no sorting of eigenvalues)
72*>
73*> (6)   if eigenvalues = diagonal blocks of the Schur form (S, T),
74*>       i.e., test the maximum over j of D(j)  where:
75*>
76*>       if alpha(j) is real:
77*>                     |alpha(j) - S(j,j)|        |beta(j) - T(j,j)|
78*>           D(j) = ------------------------ + -----------------------
79*>                  max(|alpha(j)|,|S(j,j)|)   max(|beta(j)|,|T(j,j)|)
80*>
81*>       if alpha(j) is complex:
82*>                                 | det( s S - w T ) |
83*>           D(j) = ---------------------------------------------------
84*>                  ulp max( s norm(S), |w| norm(T) )*norm( s S - w T )
85*>
86*>       and S and T are here the 2 x 2 diagonal blocks of S and T
87*>       corresponding to the j-th and j+1-th eigenvalues.
88*>       (no sorting of eigenvalues)
89*>
90*> (7)   | (A,B) - Q (S,T) Z' | / ( | (A,B) | n ulp )
91*>            (with sorting of eigenvalues).
92*>
93*> (8)   | I - QQ' | / ( n ulp ) (with sorting of eigenvalues).
94*>
95*> (9)   | I - ZZ' | / ( n ulp ) (with sorting of eigenvalues).
96*>
97*> (10)  if A is in Schur form (i.e. quasi-triangular form)
98*>       (with sorting of eigenvalues).
99*>
100*> (11)  if eigenvalues = diagonal blocks of the Schur form (S, T),
101*>       i.e. test the maximum over j of D(j)  where:
102*>
103*>       if alpha(j) is real:
104*>                     |alpha(j) - S(j,j)|        |beta(j) - T(j,j)|
105*>           D(j) = ------------------------ + -----------------------
106*>                  max(|alpha(j)|,|S(j,j)|)   max(|beta(j)|,|T(j,j)|)
107*>
108*>       if alpha(j) is complex:
109*>                                 | det( s S - w T ) |
110*>           D(j) = ---------------------------------------------------
111*>                  ulp max( s norm(S), |w| norm(T) )*norm( s S - w T )
112*>
113*>       and S and T are here the 2 x 2 diagonal blocks of S and T
114*>       corresponding to the j-th and j+1-th eigenvalues.
115*>       (with sorting of eigenvalues).
116*>
117*> (12)  if sorting worked and SDIM is the number of eigenvalues
118*>       which were SELECTed.
119*>
120*> Test Matrices
121*> =============
122*>
123*> The sizes of the test matrices are specified by an array
124*> NN(1:NSIZES); the value of each element NN(j) specifies one size.
125*> The "types" are specified by a logical array DOTYPE( 1:NTYPES ); if
126*> DOTYPE(j) is .TRUE., then matrix type "j" will be generated.
127*> Currently, the list of possible types is:
128*>
129*> (1)  ( 0, 0 )         (a pair of zero matrices)
130*>
131*> (2)  ( I, 0 )         (an identity and a zero matrix)
132*>
133*> (3)  ( 0, I )         (an identity and a zero matrix)
134*>
135*> (4)  ( I, I )         (a pair of identity matrices)
136*>
137*>         t   t
138*> (5)  ( J , J  )       (a pair of transposed Jordan blocks)
139*>
140*>                                     t                ( I   0  )
141*> (6)  ( X, Y )         where  X = ( J   0  )  and Y = (      t )
142*>                                  ( 0   I  )          ( 0   J  )
143*>                       and I is a k x k identity and J a (k+1)x(k+1)
144*>                       Jordan block; k=(N-1)/2
145*>
146*> (7)  ( D, I )         where D is diag( 0, 1,..., N-1 ) (a diagonal
147*>                       matrix with those diagonal entries.)
148*> (8)  ( I, D )
149*>
150*> (9)  ( big*D, small*I ) where "big" is near overflow and small=1/big
151*>
152*> (10) ( small*D, big*I )
153*>
154*> (11) ( big*I, small*D )
155*>
156*> (12) ( small*I, big*D )
157*>
158*> (13) ( big*D, big*I )
159*>
160*> (14) ( small*D, small*I )
161*>
162*> (15) ( D1, D2 )        where D1 is diag( 0, 0, 1, ..., N-3, 0 ) and
163*>                        D2 is diag( 0, N-3, N-4,..., 1, 0, 0 )
164*>           t   t
165*> (16) Q ( J , J ) Z     where Q and Z are random orthogonal matrices.
166*>
167*> (17) Q ( T1, T2 ) Z    where T1 and T2 are upper triangular matrices
168*>                        with random O(1) entries above the diagonal
169*>                        and diagonal entries diag(T1) =
170*>                        ( 0, 0, 1, ..., N-3, 0 ) and diag(T2) =
171*>                        ( 0, N-3, N-4,..., 1, 0, 0 )
172*>
173*> (18) Q ( T1, T2 ) Z    diag(T1) = ( 0, 0, 1, 1, s, ..., s, 0 )
174*>                        diag(T2) = ( 0, 1, 0, 1,..., 1, 0 )
175*>                        s = machine precision.
176*>
177*> (19) Q ( T1, T2 ) Z    diag(T1)=( 0,0,1,1, 1-d, ..., 1-(N-5)*d=s, 0 )
178*>                        diag(T2) = ( 0, 1, 0, 1, ..., 1, 0 )
179*>
180*>                                                        N-5
181*> (20) Q ( T1, T2 ) Z    diag(T1)=( 0, 0, 1, 1, a, ..., a   =s, 0 )
182*>                        diag(T2) = ( 0, 1, 0, 1, ..., 1, 0, 0 )
183*>
184*> (21) Q ( T1, T2 ) Z    diag(T1)=( 0, 0, 1, r1, r2, ..., r(N-4), 0 )
185*>                        diag(T2) = ( 0, 1, 0, 1, ..., 1, 0, 0 )
186*>                        where r1,..., r(N-4) are random.
187*>
188*> (22) Q ( big*T1, small*T2 ) Z    diag(T1) = ( 0, 0, 1, ..., N-3, 0 )
189*>                                  diag(T2) = ( 0, 1, ..., 1, 0, 0 )
190*>
191*> (23) Q ( small*T1, big*T2 ) Z    diag(T1) = ( 0, 0, 1, ..., N-3, 0 )
192*>                                  diag(T2) = ( 0, 1, ..., 1, 0, 0 )
193*>
194*> (24) Q ( small*T1, small*T2 ) Z  diag(T1) = ( 0, 0, 1, ..., N-3, 0 )
195*>                                  diag(T2) = ( 0, 1, ..., 1, 0, 0 )
196*>
197*> (25) Q ( big*T1, big*T2 ) Z      diag(T1) = ( 0, 0, 1, ..., N-3, 0 )
198*>                                  diag(T2) = ( 0, 1, ..., 1, 0, 0 )
199*>
200*> (26) Q ( T1, T2 ) Z     where T1 and T2 are random upper-triangular
201*>                         matrices.
202*>
203*> \endverbatim
204*
205*  Arguments:
206*  ==========
207*
208*> \param[in] NSIZES
209*> \verbatim
210*>          NSIZES is INTEGER
211*>          The number of sizes of matrices to use.  If it is zero,
212*>          SDRGES3 does nothing.  NSIZES >= 0.
213*> \endverbatim
214*>
215*> \param[in] NN
216*> \verbatim
217*>          NN is INTEGER array, dimension (NSIZES)
218*>          An array containing the sizes to be used for the matrices.
219*>          Zero values will be skipped.  NN >= 0.
220*> \endverbatim
221*>
222*> \param[in] NTYPES
223*> \verbatim
224*>          NTYPES is INTEGER
225*>          The number of elements in DOTYPE.   If it is zero, SDRGES3
226*>          does nothing.  It must be at least zero.  If it is MAXTYP+1
227*>          and NSIZES is 1, then an additional type, MAXTYP+1 is
228*>          defined, which is to use whatever matrix is in A on input.
229*>          This is only useful if DOTYPE(1:MAXTYP) is .FALSE. and
230*>          DOTYPE(MAXTYP+1) is .TRUE. .
231*> \endverbatim
232*>
233*> \param[in] DOTYPE
234*> \verbatim
235*>          DOTYPE is LOGICAL array, dimension (NTYPES)
236*>          If DOTYPE(j) is .TRUE., then for each size in NN a
237*>          matrix of that size and of type j will be generated.
238*>          If NTYPES is smaller than the maximum number of types
239*>          defined (PARAMETER MAXTYP), then types NTYPES+1 through
240*>          MAXTYP will not be generated. If NTYPES is larger
241*>          than MAXTYP, DOTYPE(MAXTYP+1) through DOTYPE(NTYPES)
242*>          will be ignored.
243*> \endverbatim
244*>
245*> \param[in,out] ISEED
246*> \verbatim
247*>          ISEED is INTEGER array, dimension (4)
248*>          On entry ISEED specifies the seed of the random number
249*>          generator. The array elements should be between 0 and 4095;
250*>          if not they will be reduced mod 4096. Also, ISEED(4) must
251*>          be odd.  The random number generator uses a linear
252*>          congruential sequence limited to small integers, and so
253*>          should produce machine independent random numbers. The
254*>          values of ISEED are changed on exit, and can be used in the
255*>          next call to SDRGES3 to continue the same random number
256*>          sequence.
257*> \endverbatim
258*>
259*> \param[in] THRESH
260*> \verbatim
261*>          THRESH is REAL
262*>          A test will count as "failed" if the "error", computed as
263*>          described above, exceeds THRESH.  Note that the error is
264*>          scaled to be O(1), so THRESH should be a reasonably small
265*>          multiple of 1, e.g., 10 or 100.  In particular, it should
266*>          not depend on the precision (single vs. double) or the size
267*>          of the matrix.  THRESH >= 0.
268*> \endverbatim
269*>
270*> \param[in] NOUNIT
271*> \verbatim
272*>          NOUNIT is INTEGER
273*>          The FORTRAN unit number for printing out error messages
274*>          (e.g., if a routine returns IINFO not equal to 0.)
275*> \endverbatim
276*>
277*> \param[in,out] A
278*> \verbatim
279*>          A is REAL array,
280*>                                       dimension(LDA, max(NN))
281*>          Used to hold the original A matrix.  Used as input only
282*>          if NTYPES=MAXTYP+1, DOTYPE(1:MAXTYP)=.FALSE., and
283*>          DOTYPE(MAXTYP+1)=.TRUE.
284*> \endverbatim
285*>
286*> \param[in] LDA
287*> \verbatim
288*>          LDA is INTEGER
289*>          The leading dimension of A, B, S, and T.
290*>          It must be at least 1 and at least max( NN ).
291*> \endverbatim
292*>
293*> \param[in,out] B
294*> \verbatim
295*>          B is REAL array,
296*>                                       dimension(LDA, max(NN))
297*>          Used to hold the original B matrix.  Used as input only
298*>          if NTYPES=MAXTYP+1, DOTYPE(1:MAXTYP)=.FALSE., and
299*>          DOTYPE(MAXTYP+1)=.TRUE.
300*> \endverbatim
301*>
302*> \param[out] S
303*> \verbatim
304*>          S is REAL array, dimension (LDA, max(NN))
305*>          The Schur form matrix computed from A by SGGES3.  On exit, S
306*>          contains the Schur form matrix corresponding to the matrix
307*>          in A.
308*> \endverbatim
309*>
310*> \param[out] T
311*> \verbatim
312*>          T is REAL array, dimension (LDA, max(NN))
313*>          The upper triangular matrix computed from B by SGGES3.
314*> \endverbatim
315*>
316*> \param[out] Q
317*> \verbatim
318*>          Q is REAL array, dimension (LDQ, max(NN))
319*>          The (left) orthogonal matrix computed by SGGES3.
320*> \endverbatim
321*>
322*> \param[in] LDQ
323*> \verbatim
324*>          LDQ is INTEGER
325*>          The leading dimension of Q and Z. It must
326*>          be at least 1 and at least max( NN ).
327*> \endverbatim
328*>
329*> \param[out] Z
330*> \verbatim
331*>          Z is REAL array, dimension( LDQ, max(NN) )
332*>          The (right) orthogonal matrix computed by SGGES3.
333*> \endverbatim
334*>
335*> \param[out] ALPHAR
336*> \verbatim
337*>          ALPHAR is REAL array, dimension (max(NN))
338*> \endverbatim
339*>
340*> \param[out] ALPHAI
341*> \verbatim
342*>          ALPHAI is REAL array, dimension (max(NN))
343*> \endverbatim
344*>
345*> \param[out] BETA
346*> \verbatim
347*>          BETA is REAL array, dimension (max(NN))
348*>
349*>          The generalized eigenvalues of (A,B) computed by SGGES3.
350*>          ( ALPHAR(k)+ALPHAI(k)*i ) / BETA(k) is the k-th
351*>          generalized eigenvalue of A and B.
352*> \endverbatim
353*>
354*> \param[out] WORK
355*> \verbatim
356*>          WORK is REAL array, dimension (LWORK)
357*> \endverbatim
358*>
359*> \param[in] LWORK
360*> \verbatim
361*>          LWORK is INTEGER
362*>          The dimension of the array WORK.
363*>          LWORK >= MAX( 10*(N+1), 3*N*N ), where N is the largest
364*>          matrix dimension.
365*> \endverbatim
366*>
367*> \param[out] RESULT
368*> \verbatim
369*>          RESULT is REAL array, dimension (15)
370*>          The values computed by the tests described above.
371*>          The values are currently limited to 1/ulp, to avoid overflow.
372*> \endverbatim
373*>
374*> \param[out] BWORK
375*> \verbatim
376*>          BWORK is LOGICAL array, dimension (N)
377*> \endverbatim
378*>
379*> \param[out] INFO
380*> \verbatim
381*>          INFO is INTEGER
382*>          = 0:  successful exit
383*>          < 0:  if INFO = -i, the i-th argument had an illegal value.
384*>          > 0:  A routine returned an error code.  INFO is the
385*>                absolute value of the INFO value returned.
386*> \endverbatim
387*
388*  Authors:
389*  ========
390*
391*> \author Univ. of Tennessee
392*> \author Univ. of California Berkeley
393*> \author Univ. of Colorado Denver
394*> \author NAG Ltd.
395*
396*> \ingroup single_eig
397*
398*  =====================================================================
399      SUBROUTINE SDRGES3( NSIZES, NN, NTYPES, DOTYPE, ISEED, THRESH,
400     $                    NOUNIT, A, LDA, B, S, T, Q, LDQ, Z, ALPHAR,
401     $                    ALPHAI, BETA, WORK, LWORK, RESULT, BWORK,
402     $                    INFO )
403*
404*  -- LAPACK test routine --
405*  -- LAPACK is a software package provided by Univ. of Tennessee,    --
406*  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
407*
408*     .. Scalar Arguments ..
409      INTEGER            INFO, LDA, LDQ, LWORK, NOUNIT, NSIZES, NTYPES
410      REAL               THRESH
411*     ..
412*     .. Array Arguments ..
413      LOGICAL            BWORK( * ), DOTYPE( * )
414      INTEGER            ISEED( 4 ), NN( * )
415      REAL               A( LDA, * ), ALPHAI( * ), ALPHAR( * ),
416     $                   B( LDA, * ), BETA( * ), Q( LDQ, * ),
417     $                   RESULT( 13 ), S( LDA, * ), T( LDA, * ),
418     $                   WORK( * ), Z( LDQ, * )
419*     ..
420*
421*  =====================================================================
422*
423*     .. Parameters ..
424      REAL               ZERO, ONE
425      PARAMETER          ( ZERO = 0.0E+0, ONE = 1.0E+0 )
426      INTEGER            MAXTYP
427      PARAMETER          ( MAXTYP = 26 )
428*     ..
429*     .. Local Scalars ..
430      LOGICAL            BADNN, ILABAD
431      CHARACTER          SORT
432      INTEGER            I, I1, IADD, IERR, IINFO, IN, ISORT, J, JC, JR,
433     $                   JSIZE, JTYPE, KNTEIG, MAXWRK, MINWRK, MTYPES,
434     $                   N, N1, NB, NERRS, NMATS, NMAX, NTEST, NTESTT,
435     $                   RSUB, SDIM
436      REAL               SAFMAX, SAFMIN, TEMP1, TEMP2, ULP, ULPINV
437*     ..
438*     .. Local Arrays ..
439      INTEGER            IASIGN( MAXTYP ), IBSIGN( MAXTYP ),
440     $                   IOLDSD( 4 ), KADD( 6 ), KAMAGN( MAXTYP ),
441     $                   KATYPE( MAXTYP ), KAZERO( MAXTYP ),
442     $                   KBMAGN( MAXTYP ), KBTYPE( MAXTYP ),
443     $                   KBZERO( MAXTYP ), KCLASS( MAXTYP ),
444     $                   KTRIAN( MAXTYP ), KZ1( 6 ), KZ2( 6 )
445      REAL               RMAGN( 0: 3 )
446*     ..
447*     .. External Functions ..
448      LOGICAL            SLCTES
449      INTEGER            ILAENV
450      REAL               SLAMCH, SLARND
451      EXTERNAL           SLCTES, ILAENV, SLAMCH, SLARND
452*     ..
453*     .. External Subroutines ..
454      EXTERNAL           ALASVM, SGET51, SGET53, SGET54, SGGES3, SLABAD,
455     $                   SLACPY, SLARFG, SLASET, SLATM4, SORM2R, XERBLA
456*     ..
457*     .. Intrinsic Functions ..
458      INTRINSIC          ABS, MAX, MIN, REAL, SIGN
459*     ..
460*     .. Data statements ..
461      DATA               KCLASS / 15*1, 10*2, 1*3 /
462      DATA               KZ1 / 0, 1, 2, 1, 3, 3 /
463      DATA               KZ2 / 0, 0, 1, 2, 1, 1 /
464      DATA               KADD / 0, 0, 0, 0, 3, 2 /
465      DATA               KATYPE / 0, 1, 0, 1, 2, 3, 4, 1, 4, 4, 1, 1, 4,
466     $                   4, 4, 2, 4, 5, 8, 7, 9, 4*4, 0 /
467      DATA               KBTYPE / 0, 0, 1, 1, 2, -3, 1, 4, 1, 1, 4, 4,
468     $                   1, 1, -4, 2, -4, 8*8, 0 /
469      DATA               KAZERO / 6*1, 2, 1, 2*2, 2*1, 2*2, 3, 1, 3,
470     $                   4*5, 4*3, 1 /
471      DATA               KBZERO / 6*1, 1, 2, 2*1, 2*2, 2*1, 4, 1, 4,
472     $                   4*6, 4*4, 1 /
473      DATA               KAMAGN / 8*1, 2, 3, 2, 3, 2, 3, 7*1, 2, 3, 3,
474     $                   2, 1 /
475      DATA               KBMAGN / 8*1, 3, 2, 3, 2, 2, 3, 7*1, 3, 2, 3,
476     $                   2, 1 /
477      DATA               KTRIAN / 16*0, 10*1 /
478      DATA               IASIGN / 6*0, 2, 0, 2*2, 2*0, 3*2, 0, 2, 3*0,
479     $                   5*2, 0 /
480      DATA               IBSIGN / 7*0, 2, 2*0, 2*2, 2*0, 2, 0, 2, 9*0 /
481*     ..
482*     .. Executable Statements ..
483*
484*     Check for errors
485*
486      INFO = 0
487*
488      BADNN = .FALSE.
489      NMAX = 1
490      DO 10 J = 1, NSIZES
491         NMAX = MAX( NMAX, NN( J ) )
492         IF( NN( J ).LT.0 )
493     $      BADNN = .TRUE.
494   10 CONTINUE
495*
496      IF( NSIZES.LT.0 ) THEN
497         INFO = -1
498      ELSE IF( BADNN ) THEN
499         INFO = -2
500      ELSE IF( NTYPES.LT.0 ) THEN
501         INFO = -3
502      ELSE IF( THRESH.LT.ZERO ) THEN
503         INFO = -6
504      ELSE IF( LDA.LE.1 .OR. LDA.LT.NMAX ) THEN
505         INFO = -9
506      ELSE IF( LDQ.LE.1 .OR. LDQ.LT.NMAX ) THEN
507         INFO = -14
508      END IF
509*
510*     Compute workspace
511*      (Note: Comments in the code beginning "Workspace:" describe the
512*       minimal amount of workspace needed at that point in the code,
513*       as well as the preferred amount for good performance.
514*       NB refers to the optimal block size for the immediately
515*       following subroutine, as returned by ILAENV.
516*
517      MINWRK = 1
518      IF( INFO.EQ.0 .AND. LWORK.GE.1 ) THEN
519         MINWRK = MAX( 10*( NMAX+1 ), 3*NMAX*NMAX )
520         NB = MAX( 1, ILAENV( 1, 'SGEQRF', ' ', NMAX, NMAX, -1, -1 ),
521     $        ILAENV( 1, 'SORMQR', 'LT', NMAX, NMAX, NMAX, -1 ),
522     $        ILAENV( 1, 'SORGQR', ' ', NMAX, NMAX, NMAX, -1 ) )
523         MAXWRK = MAX( 10*( NMAX+1 ), 2*NMAX+NMAX*NB, 3*NMAX*NMAX )
524         WORK( 1 ) = MAXWRK
525      END IF
526*
527      IF( LWORK.LT.MINWRK )
528     $   INFO = -20
529*
530      IF( INFO.NE.0 ) THEN
531         CALL XERBLA( 'SDRGES3', -INFO )
532         RETURN
533      END IF
534*
535*     Quick return if possible
536*
537      IF( NSIZES.EQ.0 .OR. NTYPES.EQ.0 )
538     $   RETURN
539*
540      SAFMIN = SLAMCH( 'Safe minimum' )
541      ULP = SLAMCH( 'Epsilon' )*SLAMCH( 'Base' )
542      SAFMIN = SAFMIN / ULP
543      SAFMAX = ONE / SAFMIN
544      CALL SLABAD( SAFMIN, SAFMAX )
545      ULPINV = ONE / ULP
546*
547*     The values RMAGN(2:3) depend on N, see below.
548*
549      RMAGN( 0 ) = ZERO
550      RMAGN( 1 ) = ONE
551*
552*     Loop over matrix sizes
553*
554      NTESTT = 0
555      NERRS = 0
556      NMATS = 0
557*
558      DO 190 JSIZE = 1, NSIZES
559         N = NN( JSIZE )
560         N1 = MAX( 1, N )
561         RMAGN( 2 ) = SAFMAX*ULP / REAL( N1 )
562         RMAGN( 3 ) = SAFMIN*ULPINV*REAL( N1 )
563*
564         IF( NSIZES.NE.1 ) THEN
565            MTYPES = MIN( MAXTYP, NTYPES )
566         ELSE
567            MTYPES = MIN( MAXTYP+1, NTYPES )
568         END IF
569*
570*        Loop over matrix types
571*
572         DO 180 JTYPE = 1, MTYPES
573            IF( .NOT.DOTYPE( JTYPE ) )
574     $         GO TO 180
575            NMATS = NMATS + 1
576            NTEST = 0
577*
578*           Save ISEED in case of an error.
579*
580            DO 20 J = 1, 4
581               IOLDSD( J ) = ISEED( J )
582   20       CONTINUE
583*
584*           Initialize RESULT
585*
586            DO 30 J = 1, 13
587               RESULT( J ) = ZERO
588   30       CONTINUE
589*
590*           Generate test matrices A and B
591*
592*           Description of control parameters:
593*
594*           KCLASS: =1 means w/o rotation, =2 means w/ rotation,
595*                   =3 means random.
596*           KATYPE: the "type" to be passed to SLATM4 for computing A.
597*           KAZERO: the pattern of zeros on the diagonal for A:
598*                   =1: ( xxx ), =2: (0, xxx ) =3: ( 0, 0, xxx, 0 ),
599*                   =4: ( 0, xxx, 0, 0 ), =5: ( 0, 0, 1, xxx, 0 ),
600*                   =6: ( 0, 1, 0, xxx, 0 ).  (xxx means a string of
601*                   non-zero entries.)
602*           KAMAGN: the magnitude of the matrix: =0: zero, =1: O(1),
603*                   =2: large, =3: small.
604*           IASIGN: 1 if the diagonal elements of A are to be
605*                   multiplied by a random magnitude 1 number, =2 if
606*                   randomly chosen diagonal blocks are to be rotated
607*                   to form 2x2 blocks.
608*           KBTYPE, KBZERO, KBMAGN, IBSIGN: the same, but for B.
609*           KTRIAN: =0: don't fill in the upper triangle, =1: do.
610*           KZ1, KZ2, KADD: used to implement KAZERO and KBZERO.
611*           RMAGN: used to implement KAMAGN and KBMAGN.
612*
613            IF( MTYPES.GT.MAXTYP )
614     $         GO TO 110
615            IINFO = 0
616            IF( KCLASS( JTYPE ).LT.3 ) THEN
617*
618*              Generate A (w/o rotation)
619*
620               IF( ABS( KATYPE( JTYPE ) ).EQ.3 ) THEN
621                  IN = 2*( ( N-1 ) / 2 ) + 1
622                  IF( IN.NE.N )
623     $               CALL SLASET( 'Full', N, N, ZERO, ZERO, A, LDA )
624               ELSE
625                  IN = N
626               END IF
627               CALL SLATM4( KATYPE( JTYPE ), IN, KZ1( KAZERO( JTYPE ) ),
628     $                      KZ2( KAZERO( JTYPE ) ), IASIGN( JTYPE ),
629     $                      RMAGN( KAMAGN( JTYPE ) ), ULP,
630     $                      RMAGN( KTRIAN( JTYPE )*KAMAGN( JTYPE ) ), 2,
631     $                      ISEED, A, LDA )
632               IADD = KADD( KAZERO( JTYPE ) )
633               IF( IADD.GT.0 .AND. IADD.LE.N )
634     $            A( IADD, IADD ) = ONE
635*
636*              Generate B (w/o rotation)
637*
638               IF( ABS( KBTYPE( JTYPE ) ).EQ.3 ) THEN
639                  IN = 2*( ( N-1 ) / 2 ) + 1
640                  IF( IN.NE.N )
641     $               CALL SLASET( 'Full', N, N, ZERO, ZERO, B, LDA )
642               ELSE
643                  IN = N
644               END IF
645               CALL SLATM4( KBTYPE( JTYPE ), IN, KZ1( KBZERO( JTYPE ) ),
646     $                      KZ2( KBZERO( JTYPE ) ), IBSIGN( JTYPE ),
647     $                      RMAGN( KBMAGN( JTYPE ) ), ONE,
648     $                      RMAGN( KTRIAN( JTYPE )*KBMAGN( JTYPE ) ), 2,
649     $                      ISEED, B, LDA )
650               IADD = KADD( KBZERO( JTYPE ) )
651               IF( IADD.NE.0 .AND. IADD.LE.N )
652     $            B( IADD, IADD ) = ONE
653*
654               IF( KCLASS( JTYPE ).EQ.2 .AND. N.GT.0 ) THEN
655*
656*                 Include rotations
657*
658*                 Generate Q, Z as Householder transformations times
659*                 a diagonal matrix.
660*
661                  DO 50 JC = 1, N - 1
662                     DO 40 JR = JC, N
663                        Q( JR, JC ) = SLARND( 3, ISEED )
664                        Z( JR, JC ) = SLARND( 3, ISEED )
665   40                CONTINUE
666                     CALL SLARFG( N+1-JC, Q( JC, JC ), Q( JC+1, JC ), 1,
667     $                            WORK( JC ) )
668                     WORK( 2*N+JC ) = SIGN( ONE, Q( JC, JC ) )
669                     Q( JC, JC ) = ONE
670                     CALL SLARFG( N+1-JC, Z( JC, JC ), Z( JC+1, JC ), 1,
671     $                            WORK( N+JC ) )
672                     WORK( 3*N+JC ) = SIGN( ONE, Z( JC, JC ) )
673                     Z( JC, JC ) = ONE
674   50             CONTINUE
675                  Q( N, N ) = ONE
676                  WORK( N ) = ZERO
677                  WORK( 3*N ) = SIGN( ONE, SLARND( 2, ISEED ) )
678                  Z( N, N ) = ONE
679                  WORK( 2*N ) = ZERO
680                  WORK( 4*N ) = SIGN( ONE, SLARND( 2, ISEED ) )
681*
682*                 Apply the diagonal matrices
683*
684                  DO 70 JC = 1, N
685                     DO 60 JR = 1, N
686                        A( JR, JC ) = WORK( 2*N+JR )*WORK( 3*N+JC )*
687     $                                A( JR, JC )
688                        B( JR, JC ) = WORK( 2*N+JR )*WORK( 3*N+JC )*
689     $                                B( JR, JC )
690   60                CONTINUE
691   70             CONTINUE
692                  CALL SORM2R( 'L', 'N', N, N, N-1, Q, LDQ, WORK, A,
693     $                         LDA, WORK( 2*N+1 ), IINFO )
694                  IF( IINFO.NE.0 )
695     $               GO TO 100
696                  CALL SORM2R( 'R', 'T', N, N, N-1, Z, LDQ, WORK( N+1 ),
697     $                         A, LDA, WORK( 2*N+1 ), IINFO )
698                  IF( IINFO.NE.0 )
699     $               GO TO 100
700                  CALL SORM2R( 'L', 'N', N, N, N-1, Q, LDQ, WORK, B,
701     $                         LDA, WORK( 2*N+1 ), IINFO )
702                  IF( IINFO.NE.0 )
703     $               GO TO 100
704                  CALL SORM2R( 'R', 'T', N, N, N-1, Z, LDQ, WORK( N+1 ),
705     $                         B, LDA, WORK( 2*N+1 ), IINFO )
706                  IF( IINFO.NE.0 )
707     $               GO TO 100
708               END IF
709            ELSE
710*
711*              Random matrices
712*
713               DO 90 JC = 1, N
714                  DO 80 JR = 1, N
715                     A( JR, JC ) = RMAGN( KAMAGN( JTYPE ) )*
716     $                             SLARND( 2, ISEED )
717                     B( JR, JC ) = RMAGN( KBMAGN( JTYPE ) )*
718     $                             SLARND( 2, ISEED )
719   80             CONTINUE
720   90          CONTINUE
721            END IF
722*
723  100       CONTINUE
724*
725            IF( IINFO.NE.0 ) THEN
726               WRITE( NOUNIT, FMT = 9999 )'Generator', IINFO, N, JTYPE,
727     $            IOLDSD
728               INFO = ABS( IINFO )
729               RETURN
730            END IF
731*
732  110       CONTINUE
733*
734            DO 120 I = 1, 13
735               RESULT( I ) = -ONE
736  120       CONTINUE
737*
738*           Test with and without sorting of eigenvalues
739*
740            DO 150 ISORT = 0, 1
741               IF( ISORT.EQ.0 ) THEN
742                  SORT = 'N'
743                  RSUB = 0
744               ELSE
745                  SORT = 'S'
746                  RSUB = 5
747               END IF
748*
749*              Call XLAENV to set the parameters used in SLAQZ0
750*
751               CALL XLAENV( 12, 10 )
752               CALL XLAENV( 13, 12 )
753               CALL XLAENV( 14, 13 )
754               CALL XLAENV( 15, 2 )
755               CALL XLAENV( 17, 10 )
756*
757*              Call SGGES3 to compute H, T, Q, Z, alpha, and beta.
758*
759               CALL SLACPY( 'Full', N, N, A, LDA, S, LDA )
760               CALL SLACPY( 'Full', N, N, B, LDA, T, LDA )
761               NTEST = 1 + RSUB + ISORT
762               RESULT( 1+RSUB+ISORT ) = ULPINV
763               CALL SGGES3( 'V', 'V', SORT, SLCTES, N, S, LDA, T, LDA,
764     $                      SDIM, ALPHAR, ALPHAI, BETA, Q, LDQ, Z, LDQ,
765     $                      WORK, LWORK, BWORK, IINFO )
766               IF( IINFO.NE.0 .AND. IINFO.NE.N+2 ) THEN
767                  RESULT( 1+RSUB+ISORT ) = ULPINV
768                  WRITE( NOUNIT, FMT = 9999 )'SGGES3', IINFO, N, JTYPE,
769     $               IOLDSD
770                  INFO = ABS( IINFO )
771                  GO TO 160
772               END IF
773*
774               NTEST = 4 + RSUB
775*
776*              Do tests 1--4 (or tests 7--9 when reordering )
777*
778               IF( ISORT.EQ.0 ) THEN
779                  CALL SGET51( 1, N, A, LDA, S, LDA, Q, LDQ, Z, LDQ,
780     $                         WORK, RESULT( 1 ) )
781                  CALL SGET51( 1, N, B, LDA, T, LDA, Q, LDQ, Z, LDQ,
782     $                         WORK, RESULT( 2 ) )
783               ELSE
784                  CALL SGET54( N, A, LDA, B, LDA, S, LDA, T, LDA, Q,
785     $                         LDQ, Z, LDQ, WORK, RESULT( 7 ) )
786               END IF
787               CALL SGET51( 3, N, A, LDA, T, LDA, Q, LDQ, Q, LDQ, WORK,
788     $                      RESULT( 3+RSUB ) )
789               CALL SGET51( 3, N, B, LDA, T, LDA, Z, LDQ, Z, LDQ, WORK,
790     $                      RESULT( 4+RSUB ) )
791*
792*              Do test 5 and 6 (or Tests 10 and 11 when reordering):
793*              check Schur form of A and compare eigenvalues with
794*              diagonals.
795*
796               NTEST = 6 + RSUB
797               TEMP1 = ZERO
798*
799               DO 130 J = 1, N
800                  ILABAD = .FALSE.
801                  IF( ALPHAI( J ).EQ.ZERO ) THEN
802                     TEMP2 = ( ABS( ALPHAR( J )-S( J, J ) ) /
803     $                       MAX( SAFMIN, ABS( ALPHAR( J ) ), ABS( S( J,
804     $                       J ) ) )+ABS( BETA( J )-T( J, J ) ) /
805     $                       MAX( SAFMIN, ABS( BETA( J ) ), ABS( T( J,
806     $                       J ) ) ) ) / ULP
807*
808                     IF( J.LT.N ) THEN
809                        IF( S( J+1, J ).NE.ZERO ) THEN
810                           ILABAD = .TRUE.
811                           RESULT( 5+RSUB ) = ULPINV
812                        END IF
813                     END IF
814                     IF( J.GT.1 ) THEN
815                        IF( S( J, J-1 ).NE.ZERO ) THEN
816                           ILABAD = .TRUE.
817                           RESULT( 5+RSUB ) = ULPINV
818                        END IF
819                     END IF
820*
821                  ELSE
822                     IF( ALPHAI( J ).GT.ZERO ) THEN
823                        I1 = J
824                     ELSE
825                        I1 = J - 1
826                     END IF
827                     IF( I1.LE.0 .OR. I1.GE.N ) THEN
828                        ILABAD = .TRUE.
829                     ELSE IF( I1.LT.N-1 ) THEN
830                        IF( S( I1+2, I1+1 ).NE.ZERO ) THEN
831                           ILABAD = .TRUE.
832                           RESULT( 5+RSUB ) = ULPINV
833                        END IF
834                     ELSE IF( I1.GT.1 ) THEN
835                        IF( S( I1, I1-1 ).NE.ZERO ) THEN
836                           ILABAD = .TRUE.
837                           RESULT( 5+RSUB ) = ULPINV
838                        END IF
839                     END IF
840                     IF( .NOT.ILABAD ) THEN
841                        CALL SGET53( S( I1, I1 ), LDA, T( I1, I1 ), LDA,
842     $                               BETA( J ), ALPHAR( J ),
843     $                               ALPHAI( J ), TEMP2, IERR )
844                        IF( IERR.GE.3 ) THEN
845                           WRITE( NOUNIT, FMT = 9998 )IERR, J, N,
846     $                        JTYPE, IOLDSD
847                           INFO = ABS( IERR )
848                        END IF
849                     ELSE
850                        TEMP2 = ULPINV
851                     END IF
852*
853                  END IF
854                  TEMP1 = MAX( TEMP1, TEMP2 )
855                  IF( ILABAD ) THEN
856                     WRITE( NOUNIT, FMT = 9997 )J, N, JTYPE, IOLDSD
857                  END IF
858  130          CONTINUE
859               RESULT( 6+RSUB ) = TEMP1
860*
861               IF( ISORT.GE.1 ) THEN
862*
863*                 Do test 12
864*
865                  NTEST = 12
866                  RESULT( 12 ) = ZERO
867                  KNTEIG = 0
868                  DO 140 I = 1, N
869                     IF( SLCTES( ALPHAR( I ), ALPHAI( I ),
870     $                   BETA( I ) ) .OR. SLCTES( ALPHAR( I ),
871     $                   -ALPHAI( I ), BETA( I ) ) ) THEN
872                        KNTEIG = KNTEIG + 1
873                     END IF
874                     IF( I.LT.N ) THEN
875                        IF( ( SLCTES( ALPHAR( I+1 ), ALPHAI( I+1 ),
876     $                      BETA( I+1 ) ) .OR. SLCTES( ALPHAR( I+1 ),
877     $                      -ALPHAI( I+1 ), BETA( I+1 ) ) ) .AND.
878     $                      ( .NOT.( SLCTES( ALPHAR( I ), ALPHAI( I ),
879     $                      BETA( I ) ) .OR. SLCTES( ALPHAR( I ),
880     $                      -ALPHAI( I ), BETA( I ) ) ) ) .AND.
881     $                      IINFO.NE.N+2 ) THEN
882                           RESULT( 12 ) = ULPINV
883                        END IF
884                     END IF
885  140             CONTINUE
886                  IF( SDIM.NE.KNTEIG ) THEN
887                     RESULT( 12 ) = ULPINV
888                  END IF
889               END IF
890*
891  150       CONTINUE
892*
893*           End of Loop -- Check for RESULT(j) > THRESH
894*
895  160       CONTINUE
896*
897            NTESTT = NTESTT + NTEST
898*
899*           Print out tests which fail.
900*
901            DO 170 JR = 1, NTEST
902               IF( RESULT( JR ).GE.THRESH ) THEN
903*
904*                 If this is the first test to fail,
905*                 print a header to the data file.
906*
907                  IF( NERRS.EQ.0 ) THEN
908                     WRITE( NOUNIT, FMT = 9996 )'SGS'
909*
910*                    Matrix types
911*
912                     WRITE( NOUNIT, FMT = 9995 )
913                     WRITE( NOUNIT, FMT = 9994 )
914                     WRITE( NOUNIT, FMT = 9993 )'Orthogonal'
915*
916*                    Tests performed
917*
918                     WRITE( NOUNIT, FMT = 9992 )'orthogonal', '''',
919     $                  'transpose', ( '''', J = 1, 8 )
920*
921                  END IF
922                  NERRS = NERRS + 1
923                  IF( RESULT( JR ).LT.10000.0 ) THEN
924                     WRITE( NOUNIT, FMT = 9991 )N, JTYPE, IOLDSD, JR,
925     $                  RESULT( JR )
926                  ELSE
927                     WRITE( NOUNIT, FMT = 9990 )N, JTYPE, IOLDSD, JR,
928     $                  RESULT( JR )
929                  END IF
930               END IF
931  170       CONTINUE
932*
933  180    CONTINUE
934  190 CONTINUE
935*
936*     Summary
937*
938      CALL ALASVM( 'SGS', NOUNIT, NERRS, NTESTT, 0 )
939*
940      WORK( 1 ) = MAXWRK
941*
942      RETURN
943*
944 9999 FORMAT( ' SDRGES3: ', A, ' returned INFO=', I6, '.', / 9X, 'N=',
945     $      I6, ', JTYPE=', I6, ', ISEED=(', 4( I4, ',' ), I5, ')' )
946*
947 9998 FORMAT( ' SDRGES3: SGET53 returned INFO=', I1, ' for eigenvalue ',
948     $      I6, '.', / 9X, 'N=', I6, ', JTYPE=', I6, ', ISEED=(',
949     $      4( I4, ',' ), I5, ')' )
950*
951 9997 FORMAT( ' SDRGES3: S not in Schur form at eigenvalue ', I6, '.',
952     $      / 9X, 'N=', I6, ', JTYPE=', I6, ', ISEED=(', 3( I5, ',' ),
953     $      I5, ')' )
954*
955 9996 FORMAT( / 1X, A3, ' -- Real Generalized Schur form driver' )
956*
957 9995 FORMAT( ' Matrix types (see SDRGES3 for details): ' )
958*
959 9994 FORMAT( ' Special Matrices:', 23X,
960     $      '(J''=transposed Jordan block)',
961     $      / '   1=(0,0)  2=(I,0)  3=(0,I)  4=(I,I)  5=(J'',J'')  ',
962     $      '6=(diag(J'',I), diag(I,J''))', / ' Diagonal Matrices:  ( ',
963     $      'D=diag(0,1,2,...) )', / '   7=(D,I)   9=(large*D, small*I',
964     $      ')  11=(large*I, small*D)  13=(large*D, large*I)', /
965     $      '   8=(I,D)  10=(small*D, large*I)  12=(small*I, large*D) ',
966     $      ' 14=(small*D, small*I)', / '  15=(D, reversed D)' )
967 9993 FORMAT( ' Matrices Rotated by Random ', A, ' Matrices U, V:',
968     $      / '  16=Transposed Jordan Blocks             19=geometric ',
969     $      'alpha, beta=0,1', / '  17=arithm. alpha&beta             ',
970     $      '      20=arithmetic alpha, beta=0,1', / '  18=clustered ',
971     $      'alpha, beta=0,1            21=random alpha, beta=0,1',
972     $      / ' Large & Small Matrices:', / '  22=(large, small)   ',
973     $      '23=(small,large)    24=(small,small)    25=(large,large)',
974     $      / '  26=random O(1) matrices.' )
975*
976 9992 FORMAT( / ' Tests performed:  (S is Schur, T is triangular, ',
977     $      'Q and Z are ', A, ',', / 19X,
978     $      'l and r are the appropriate left and right', / 19X,
979     $      'eigenvectors, resp., a is alpha, b is beta, and', / 19X, A,
980     $      ' means ', A, '.)', / ' Without ordering: ',
981     $      / '  1 = | A - Q S Z', A,
982     $      ' | / ( |A| n ulp )      2 = | B - Q T Z', A,
983     $      ' | / ( |B| n ulp )', / '  3 = | I - QQ', A,
984     $      ' | / ( n ulp )             4 = | I - ZZ', A,
985     $      ' | / ( n ulp )', / '  5 = A is in Schur form S',
986     $      / '  6 = difference between (alpha,beta)',
987     $      ' and diagonals of (S,T)', / ' With ordering: ',
988     $      / '  7 = | (A,B) - Q (S,T) Z', A,
989     $      ' | / ( |(A,B)| n ulp )  ', / '  8 = | I - QQ', A,
990     $      ' | / ( n ulp )            9 = | I - ZZ', A,
991     $      ' | / ( n ulp )', / ' 10 = A is in Schur form S',
992     $      / ' 11 = difference between (alpha,beta) and diagonals',
993     $      ' of (S,T)', / ' 12 = SDIM is the correct number of ',
994     $      'selected eigenvalues', / )
995 9991 FORMAT( ' Matrix order=', I5, ', type=', I2, ', seed=',
996     $      4( I4, ',' ), ' result ', I2, ' is', 0P, F8.2 )
997 9990 FORMAT( ' Matrix order=', I5, ', type=', I2, ', seed=',
998     $      4( I4, ',' ), ' result ', I2, ' is', 1P, E10.3 )
999*
1000*     End of SDRGES3
1001*
1002      END
1003