LAPACK  3.6.1
LAPACK: Linear Algebra PACKage
subroutine cebchvxx ( real  THRESH,
character*3  PATH 
)

CEBCHVXX

Purpose:

  CEBCHVXX will run CGESVXX on a series of Hilbert matrices and then
  compare the error bounds returned by CGESVXX to see if the returned
  answer indeed falls within those bounds.

  Eight test ratios will be computed.  The tests will pass if they are .LT.
  THRESH.  There are two cases that are determined by 1 / (SQRT( N ) * EPS).
  If that value is .LE. to the component wise reciprocal condition number,
  it uses the guaranteed case, other wise it uses the unguaranteed case.

  Test ratios:
     Let Xc be X_computed and Xt be X_truth.
     The norm used is the infinity norm.

     Let A be the guaranteed case and B be the unguaranteed case.

       1. Normwise guaranteed forward error bound.
       A: norm ( abs( Xc - Xt ) / norm ( Xt ) .LE. ERRBND( *, nwise_i, bnd_i ) and
          ERRBND( *, nwise_i, bnd_i ) .LE. MAX(SQRT(N),10) * EPS.
          If these conditions are met, the test ratio is set to be
          ERRBND( *, nwise_i, bnd_i ) / MAX(SQRT(N), 10).  Otherwise it is 1/EPS.
       B: For this case, CGESVXX should just return 1.  If it is less than
          one, treat it the same as in 1A.  Otherwise it fails. (Set test
          ratio to ERRBND( *, nwise_i, bnd_i ) * THRESH?)

       2. Componentwise guaranteed forward error bound.
       A: norm ( abs( Xc(j) - Xt(j) ) ) / norm (Xt(j)) .LE. ERRBND( *, cwise_i, bnd_i )
          for all j .AND. ERRBND( *, cwise_i, bnd_i ) .LE. MAX(SQRT(N), 10) * EPS.
          If these conditions are met, the test ratio is set to be
          ERRBND( *, cwise_i, bnd_i ) / MAX(SQRT(N), 10).  Otherwise it is 1/EPS.
       B: Same as normwise test ratio.

       3. Backwards error.
       A: The test ratio is set to BERR/EPS.
       B: Same test ratio.

       4. Reciprocal condition number.
       A: A condition number is computed with Xt and compared with the one
          returned from CGESVXX.  Let RCONDc be the RCOND returned by CGESVXX
          and RCONDt be the RCOND from the truth value.  Test ratio is set to
          MAX(RCONDc/RCONDt, RCONDt/RCONDc).
       B: Test ratio is set to 1 / (EPS * RCONDc).

       5. Reciprocal normwise condition number.
       A: The test ratio is set to
          MAX(ERRBND( *, nwise_i, cond_i ) / NCOND, NCOND / ERRBND( *, nwise_i, cond_i )).
       B: Test ratio is set to 1 / (EPS * ERRBND( *, nwise_i, cond_i )).

       6. Reciprocal componentwise condition number.
       A: Test ratio is set to
          MAX(ERRBND( *, cwise_i, cond_i ) / CCOND, CCOND / ERRBND( *, cwise_i, cond_i )).
       B: Test ratio is set to 1 / (EPS * ERRBND( *, cwise_i, cond_i )).

     .. Parameters ..
     NMAX is determined by the largest number in the inverse of the hilbert
     matrix.  Precision is exhausted when the largest entry in it is greater
     than 2 to the power of the number of bits in the fraction of the data
     type used plus one, which is 24 for single precision.
     NMAX should be 6 for single and 11 for double.
Author
Univ. of Tennessee
Univ. of California Berkeley
Univ. of Colorado Denver
NAG Ltd.
Date
November 2011

Definition at line 98 of file cebchvxx.f.

98  IMPLICIT NONE
99 * .. Scalar Arguments ..
100  REAL thresh
101  CHARACTER*3 path
102 
103  INTEGER nmax, nparams, nerrbnd, ntests, kl, ku
104  parameter (nmax = 6, nparams = 2, nerrbnd = 3,
105  $ ntests = 6)
106 
107 * .. Local Scalars ..
108  INTEGER n, nrhs, info, i ,j, k, nfail, lda,
109  $ n_aux_tests, ldab, ldafb
110  CHARACTER fact, trans, uplo, equed
111  CHARACTER*2 c2
112  CHARACTER(3) nguar, cguar
113  LOGICAL printed_guide
114  REAL ncond, ccond, m, normdif, normt, rcond,
115  $ rnorm, rinorm, sumr, sumri, eps,
116  $ berr(nmax), rpvgrw, orcond,
117  $ cwise_err, nwise_err, cwise_bnd, nwise_bnd,
118  $ cwise_rcond, nwise_rcond,
119  $ condthresh, errthresh
120  COMPLEX zdum
121 
122 * .. Local Arrays ..
123  REAL tstrat(ntests), rinv(nmax), params(nparams),
124  $ s(nmax), r(nmax),c(nmax),rwork(3*nmax),
125  $ diff(nmax, nmax),
126  $ errbnd_n(nmax*3), errbnd_c(nmax*3)
127  INTEGER ipiv(nmax)
128  COMPLEX a(nmax,nmax),invhilb(nmax,nmax),x(nmax,nmax),
129  $ work(nmax*3*5), af(nmax, nmax),b(nmax, nmax),
130  $ acopy(nmax, nmax),
131  $ ab( (nmax-1)+(nmax-1)+1, nmax ),
132  $ abcopy( (nmax-1)+(nmax-1)+1, nmax ),
133  $ afb( 2*(nmax-1)+(nmax-1)+1, nmax )
134 
135 * .. External Functions ..
136  REAL slamch
137 
138 * .. External Subroutines ..
139  EXTERNAL clahilb, cgesvxx, csysvxx, cposvxx,
140  $ cgbsvxx, clacpy, lsamen
141  LOGICAL lsamen
142 
143 * .. Intrinsic Functions ..
144  INTRINSIC sqrt, max, abs, REAL, aimag
145 
146 * .. Statement Functions ..
147  REAL cabs1
148 * ..
149 * .. Statement Function Definitions ..
150  cabs1( zdum ) = abs( REAL( ZDUM ) ) + abs( aimag( zdum ) )
151 
152 * .. Parameters ..
153  INTEGER nwise_i, cwise_i
154  parameter (nwise_i = 1, cwise_i = 1)
155  INTEGER bnd_i, cond_i
156  parameter (bnd_i = 2, cond_i = 3)
157 
158 * Create the loop to test out the Hilbert matrices
159 
160  fact = 'E'
161  uplo = 'U'
162  trans = 'N'
163  equed = 'N'
164  eps = slamch('Epsilon')
165  nfail = 0
166  n_aux_tests = 0
167  lda = nmax
168  ldab = (nmax-1)+(nmax-1)+1
169  ldafb = 2*(nmax-1)+(nmax-1)+1
170  c2 = path( 2: 3 )
171 
172 * Main loop to test the different Hilbert Matrices.
173 
174  printed_guide = .false.
175 
176  DO n = 1 , nmax
177  params(1) = -1
178  params(2) = -1
179 
180  kl = n-1
181  ku = n-1
182  nrhs = n
183  m = max(sqrt(REAL(n)), 10.0)
184 
185 * Generate the Hilbert matrix, its inverse, and the
186 * right hand side, all scaled by the LCM(1,..,2N-1).
187  CALL clahilb(n, n, a, lda, invhilb, lda, b,
188  $ lda, work, info, path)
189 
190 * Copy A into ACOPY.
191  CALL clacpy('ALL', n, n, a, nmax, acopy, nmax)
192 
193 * Store A in band format for GB tests
194  DO j = 1, n
195  DO i = 1, kl+ku+1
196  ab( i, j ) = (0.0e+0,0.0e+0)
197  END DO
198  END DO
199  DO j = 1, n
200  DO i = max( 1, j-ku ), min( n, j+kl )
201  ab( ku+1+i-j, j ) = a( i, j )
202  END DO
203  END DO
204 
205 * Copy AB into ABCOPY.
206  DO j = 1, n
207  DO i = 1, kl+ku+1
208  abcopy( i, j ) = (0.0e+0,0.0e+0)
209  END DO
210  END DO
211  CALL clacpy('ALL', kl+ku+1, n, ab, ldab, abcopy, ldab)
212 
213 * Call C**SVXX with default PARAMS and N_ERR_BND = 3.
214  IF ( lsamen( 2, c2, 'SY' ) ) THEN
215  CALL csysvxx(fact, uplo, n, nrhs, acopy, lda, af, lda,
216  $ ipiv, equed, s, b, lda, x, lda, orcond,
217  $ rpvgrw, berr, nerrbnd, errbnd_n, errbnd_c, nparams,
218  $ params, work, rwork, info)
219  ELSE IF ( lsamen( 2, c2, 'PO' ) ) THEN
220  CALL cposvxx(fact, uplo, n, nrhs, acopy, lda, af, lda,
221  $ equed, s, b, lda, x, lda, orcond,
222  $ rpvgrw, berr, nerrbnd, errbnd_n, errbnd_c, nparams,
223  $ params, work, rwork, info)
224  ELSE IF ( lsamen( 2, c2, 'HE' ) ) THEN
225  CALL chesvxx(fact, uplo, n, nrhs, acopy, lda, af, lda,
226  $ ipiv, equed, s, b, lda, x, lda, orcond,
227  $ rpvgrw, berr, nerrbnd, errbnd_n, errbnd_c, nparams,
228  $ params, work, rwork, info)
229  ELSE IF ( lsamen( 2, c2, 'GB' ) ) THEN
230  CALL cgbsvxx(fact, trans, n, kl, ku, nrhs, abcopy,
231  $ ldab, afb, ldafb, ipiv, equed, r, c, b,
232  $ lda, x, lda, orcond, rpvgrw, berr, nerrbnd,
233  $ errbnd_n, errbnd_c, nparams, params, work, rwork,
234  $ info)
235  ELSE
236  CALL cgesvxx(fact, trans, n, nrhs, acopy, lda, af, lda,
237  $ ipiv, equed, r, c, b, lda, x, lda, orcond,
238  $ rpvgrw, berr, nerrbnd, errbnd_n, errbnd_c, nparams,
239  $ params, work, rwork, info)
240  END IF
241 
242  n_aux_tests = n_aux_tests + 1
243  IF (orcond .LT. eps) THEN
244 ! Either factorization failed or the matrix is flagged, and 1 <=
245 ! INFO <= N+1. We don't decide based on rcond anymore.
246 ! IF (INFO .EQ. 0 .OR. INFO .GT. N+1) THEN
247 ! NFAIL = NFAIL + 1
248 ! WRITE (*, FMT=8000) N, INFO, ORCOND, RCOND
249 ! END IF
250  ELSE
251 ! Either everything succeeded (INFO == 0) or some solution failed
252 ! to converge (INFO > N+1).
253  IF (info .GT. 0 .AND. info .LE. n+1) THEN
254  nfail = nfail + 1
255  WRITE (*, fmt=8000) c2, n, info, orcond, rcond
256  END IF
257  END IF
258 
259 * Calculating the difference between C**SVXX's X and the true X.
260  DO i = 1,n
261  DO j =1,nrhs
262  diff(i,j) = x(i,j) - invhilb(i,j)
263  END DO
264  END DO
265 
266 * Calculating the RCOND
267  rnorm = 0
268  rinorm = 0
269  IF ( lsamen( 2, c2, 'PO' ) .OR. lsamen( 2, c2, 'SY' ) .OR.
270  $ lsamen( 2, c2, 'HE' ) ) THEN
271  DO i = 1, n
272  sumr = 0
273  sumri = 0
274  DO j = 1, n
275  sumr = sumr + s(i) * cabs1(a(i,j)) * s(j)
276  sumri = sumri + cabs1(invhilb(i, j)) / (s(j) * s(i))
277  END DO
278  rnorm = max(rnorm,sumr)
279  rinorm = max(rinorm,sumri)
280  END DO
281  ELSE IF ( lsamen( 2, c2, 'GE' ) .OR. lsamen( 2, c2, 'GB' ) )
282  $ THEN
283  DO i = 1, n
284  sumr = 0
285  sumri = 0
286  DO j = 1, n
287  sumr = sumr + r(i) * cabs1(a(i,j)) * c(j)
288  sumri = sumri + cabs1(invhilb(i, j)) / (r(j) * c(i))
289  END DO
290  rnorm = max(rnorm,sumr)
291  rinorm = max(rinorm,sumri)
292  END DO
293  END IF
294 
295  rnorm = rnorm / cabs1(a(1, 1))
296  rcond = 1.0/(rnorm * rinorm)
297 
298 * Calculating the R for normwise rcond.
299  DO i = 1, n
300  rinv(i) = 0.0
301  END DO
302  DO j = 1, n
303  DO i = 1, n
304  rinv(i) = rinv(i) + cabs1(a(i,j))
305  END DO
306  END DO
307 
308 * Calculating the Normwise rcond.
309  rinorm = 0.0
310  DO i = 1, n
311  sumri = 0.0
312  DO j = 1, n
313  sumri = sumri + cabs1(invhilb(i,j) * rinv(j))
314  END DO
315  rinorm = max(rinorm, sumri)
316  END DO
317 
318 ! invhilb is the inverse *unscaled* Hilbert matrix, so scale its norm
319 ! by 1/A(1,1) to make the scaling match A (the scaled Hilbert matrix)
320  ncond = cabs1(a(1,1)) / rinorm
321 
322  condthresh = m * eps
323  errthresh = m * eps
324 
325  DO k = 1, nrhs
326  normt = 0.0
327  normdif = 0.0
328  cwise_err = 0.0
329  DO i = 1, n
330  normt = max(cabs1(invhilb(i, k)), normt)
331  normdif = max(cabs1(x(i,k) - invhilb(i,k)), normdif)
332  IF (invhilb(i,k) .NE. 0.0) THEN
333  cwise_err = max(cabs1(x(i,k) - invhilb(i,k))
334  $ /cabs1(invhilb(i,k)), cwise_err)
335  ELSE IF (x(i, k) .NE. 0.0) THEN
336  cwise_err = slamch('OVERFLOW')
337  END IF
338  END DO
339  IF (normt .NE. 0.0) THEN
340  nwise_err = normdif / normt
341  ELSE IF (normdif .NE. 0.0) THEN
342  nwise_err = slamch('OVERFLOW')
343  ELSE
344  nwise_err = 0.0
345  ENDIF
346 
347  DO i = 1, n
348  rinv(i) = 0.0
349  END DO
350  DO j = 1, n
351  DO i = 1, n
352  rinv(i) = rinv(i) + cabs1(a(i, j) * invhilb(j, k))
353  END DO
354  END DO
355  rinorm = 0.0
356  DO i = 1, n
357  sumri = 0.0
358  DO j = 1, n
359  sumri = sumri
360  $ + cabs1(invhilb(i, j) * rinv(j) / invhilb(i, k))
361  END DO
362  rinorm = max(rinorm, sumri)
363  END DO
364 ! invhilb is the inverse *unscaled* Hilbert matrix, so scale its norm
365 ! by 1/A(1,1) to make the scaling match A (the scaled Hilbert matrix)
366  ccond = cabs1(a(1,1))/rinorm
367 
368 ! Forward error bound tests
369  nwise_bnd = errbnd_n(k + (bnd_i-1)*nrhs)
370  cwise_bnd = errbnd_c(k + (bnd_i-1)*nrhs)
371  nwise_rcond = errbnd_n(k + (cond_i-1)*nrhs)
372  cwise_rcond = errbnd_c(k + (cond_i-1)*nrhs)
373 ! write (*,*) 'nwise : ', n, k, ncond, nwise_rcond,
374 ! $ condthresh, ncond.ge.condthresh
375 ! write (*,*) 'nwise2: ', k, nwise_bnd, nwise_err, errthresh
376  IF (ncond .GE. condthresh) THEN
377  nguar = 'YES'
378  IF (nwise_bnd .GT. errthresh) THEN
379  tstrat(1) = 1/(2.0*eps)
380  ELSE
381  IF (nwise_bnd .NE. 0.0) THEN
382  tstrat(1) = nwise_err / nwise_bnd
383  ELSE IF (nwise_err .NE. 0.0) THEN
384  tstrat(1) = 1/(16.0*eps)
385  ELSE
386  tstrat(1) = 0.0
387  END IF
388  IF (tstrat(1) .GT. 1.0) THEN
389  tstrat(1) = 1/(4.0*eps)
390  END IF
391  END IF
392  ELSE
393  nguar = 'NO'
394  IF (nwise_bnd .LT. 1.0) THEN
395  tstrat(1) = 1/(8.0*eps)
396  ELSE
397  tstrat(1) = 1.0
398  END IF
399  END IF
400 ! write (*,*) 'cwise : ', n, k, ccond, cwise_rcond,
401 ! $ condthresh, ccond.ge.condthresh
402 ! write (*,*) 'cwise2: ', k, cwise_bnd, cwise_err, errthresh
403  IF (ccond .GE. condthresh) THEN
404  cguar = 'YES'
405  IF (cwise_bnd .GT. errthresh) THEN
406  tstrat(2) = 1/(2.0*eps)
407  ELSE
408  IF (cwise_bnd .NE. 0.0) THEN
409  tstrat(2) = cwise_err / cwise_bnd
410  ELSE IF (cwise_err .NE. 0.0) THEN
411  tstrat(2) = 1/(16.0*eps)
412  ELSE
413  tstrat(2) = 0.0
414  END IF
415  IF (tstrat(2) .GT. 1.0) tstrat(2) = 1/(4.0*eps)
416  END IF
417  ELSE
418  cguar = 'NO'
419  IF (cwise_bnd .LT. 1.0) THEN
420  tstrat(2) = 1/(8.0*eps)
421  ELSE
422  tstrat(2) = 1.0
423  END IF
424  END IF
425 
426 ! Backwards error test
427  tstrat(3) = berr(k)/eps
428 
429 ! Condition number tests
430  tstrat(4) = rcond / orcond
431  IF (rcond .GE. condthresh .AND. tstrat(4) .LT. 1.0)
432  $ tstrat(4) = 1.0 / tstrat(4)
433 
434  tstrat(5) = ncond / nwise_rcond
435  IF (ncond .GE. condthresh .AND. tstrat(5) .LT. 1.0)
436  $ tstrat(5) = 1.0 / tstrat(5)
437 
438  tstrat(6) = ccond / nwise_rcond
439  IF (ccond .GE. condthresh .AND. tstrat(6) .LT. 1.0)
440  $ tstrat(6) = 1.0 / tstrat(6)
441 
442  DO i = 1, ntests
443  IF (tstrat(i) .GT. thresh) THEN
444  IF (.NOT.printed_guide) THEN
445  WRITE(*,*)
446  WRITE( *, 9996) 1
447  WRITE( *, 9995) 2
448  WRITE( *, 9994) 3
449  WRITE( *, 9993) 4
450  WRITE( *, 9992) 5
451  WRITE( *, 9991) 6
452  WRITE( *, 9990) 7
453  WRITE( *, 9989) 8
454  WRITE(*,*)
455  printed_guide = .true.
456  END IF
457  WRITE( *, 9999) c2, n, k, nguar, cguar, i, tstrat(i)
458  nfail = nfail + 1
459  END IF
460  END DO
461  END DO
462 
463 c$$$ WRITE(*,*)
464 c$$$ WRITE(*,*) 'Normwise Error Bounds'
465 c$$$ WRITE(*,*) 'Guaranteed error bound: ',ERRBND(NRHS,nwise_i,bnd_i)
466 c$$$ WRITE(*,*) 'Reciprocal condition number: ',ERRBND(NRHS,nwise_i,cond_i)
467 c$$$ WRITE(*,*) 'Raw error estimate: ',ERRBND(NRHS,nwise_i,rawbnd_i)
468 c$$$ WRITE(*,*)
469 c$$$ WRITE(*,*) 'Componentwise Error Bounds'
470 c$$$ WRITE(*,*) 'Guaranteed error bound: ',ERRBND(NRHS,cwise_i,bnd_i)
471 c$$$ WRITE(*,*) 'Reciprocal condition number: ',ERRBND(NRHS,cwise_i,cond_i)
472 c$$$ WRITE(*,*) 'Raw error estimate: ',ERRBND(NRHS,cwise_i,rawbnd_i)
473 c$$$ print *, 'Info: ', info
474 c$$$ WRITE(*,*)
475 * WRITE(*,*) 'TSTRAT: ',TSTRAT
476 
477  END DO
478 
479  WRITE(*,*)
480  IF( nfail .GT. 0 ) THEN
481  WRITE(*,9998) c2, nfail, ntests*n+n_aux_tests
482  ELSE
483  WRITE(*,9997) c2
484  END IF
485  9999 FORMAT( ' C', a2, 'SVXX: N =', i2, ', RHS = ', i2,
486  $ ', NWISE GUAR. = ', a, ', CWISE GUAR. = ', a,
487  $ ' test(',i1,') =', g12.5 )
488  9998 FORMAT( ' C', a2, 'SVXX: ', i6, ' out of ', i6,
489  $ ' tests failed to pass the threshold' )
490  9997 FORMAT( ' C', a2, 'SVXX passed the tests of error bounds' )
491 * Test ratios.
492  9996 FORMAT( 3x, i2, ': Normwise guaranteed forward error', / 5x,
493  $ 'Guaranteed case: if norm ( abs( Xc - Xt )',
494  $ .LE.' / norm ( Xt ) ERRBND( *, nwise_i, bnd_i ), then',
495  $ / 5x,
496  $ .LE.'ERRBND( *, nwise_i, bnd_i ) MAX(SQRT(N), 10) * EPS')
497  9995 FORMAT( 3x, i2, ': Componentwise guaranteed forward error' )
498  9994 FORMAT( 3x, i2, ': Backwards error' )
499  9993 FORMAT( 3x, i2, ': Reciprocal condition number' )
500  9992 FORMAT( 3x, i2, ': Reciprocal normwise condition number' )
501  9991 FORMAT( 3x, i2, ': Raw normwise error estimate' )
502  9990 FORMAT( 3x, i2, ': Reciprocal componentwise condition number' )
503  9989 FORMAT( 3x, i2, ': Raw componentwise error estimate' )
504 
505  8000 FORMAT( ' C', a2, 'SVXX: N =', i2, ', INFO = ', i3,
506  $ ', ORCOND = ', g12.5, ', real RCOND = ', g12.5 )
507 
subroutine cposvxx(FACT, UPLO, N, NRHS, A, LDA, AF, LDAF, EQUED, S, B, LDB, X, LDX, RCOND, RPVGRW, BERR, N_ERR_BNDS, ERR_BNDS_NORM, ERR_BNDS_COMP, NPARAMS, PARAMS, WORK, RWORK, INFO)
CPOSVXX computes the solution to system of linear equations A * X = B for PO matrices ...
Definition: cposvxx.f:498
subroutine clahilb(N, NRHS, A, LDA, X, LDX, B, LDB, WORK, INFO, PATH)
CLAHILB
Definition: clahilb.f:136
logical function lsamen(N, CA, CB)
LSAMEN
Definition: lsamen.f:76
subroutine csysvxx(FACT, UPLO, N, NRHS, A, LDA, AF, LDAF, IPIV, EQUED, S, B, LDB, X, LDX, RCOND, RPVGRW, BERR, N_ERR_BNDS, ERR_BNDS_NORM, ERR_BNDS_COMP, NPARAMS, PARAMS, WORK, RWORK, INFO)
CSYSVXX computes the solution to system of linear equations A * X = B for SY matrices ...
Definition: csysvxx.f:511
subroutine cgbsvxx(FACT, TRANS, N, KL, KU, NRHS, AB, LDAB, AFB, LDAFB, IPIV, EQUED, R, C, B, LDB, X, LDX, RCOND, RPVGRW, BERR, N_ERR_BNDS, ERR_BNDS_NORM, ERR_BNDS_COMP, NPARAMS, PARAMS, WORK, RWORK, INFO)
CGBSVXX computes the solution to system of linear equations A * X = B for GB matrices ...
Definition: cgbsvxx.f:565
subroutine clacpy(UPLO, M, N, A, LDA, B, LDB)
CLACPY copies all or part of one two-dimensional array to another.
Definition: clacpy.f:105
real function slamch(CMACH)
SLAMCH
Definition: slamch.f:69
subroutine cgesvxx(FACT, TRANS, N, NRHS, A, LDA, AF, LDAF, IPIV, EQUED, R, C, B, LDB, X, LDX, RCOND, RPVGRW, BERR, N_ERR_BNDS, ERR_BNDS_NORM, ERR_BNDS_COMP, NPARAMS, PARAMS, WORK, RWORK, INFO)
CGESVXX computes the solution to system of linear equations A * X = B for GE matrices ...
Definition: cgesvxx.f:545
subroutine chesvxx(FACT, UPLO, N, NRHS, A, LDA, AF, LDAF, IPIV, EQUED, S, B, LDB, X, LDX, RCOND, RPVGRW, BERR, N_ERR_BNDS, ERR_BNDS_NORM, ERR_BNDS_COMP, NPARAMS, PARAMS, WORK, RWORK, INFO)
CHESVXX computes the solution to system of linear equations A * X = B for HE matrices ...
Definition: chesvxx.f:511

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