1 |
C $Header: /u/gcmpack/MITgcm/model/src/cg2d.F,v 1.52 2009/05/16 13:42:15 jmc Exp $ |
2 |
C $Name: $ |
3 |
|
4 |
#include "CPP_OPTIONS.h" |
5 |
#ifdef TARGET_NEC_SX |
6 |
C set a sensible default for the outer loop unrolling parameter that can |
7 |
C be overriden in the Makefile with the DEFINES macro or in CPP_OPTIONS.h |
8 |
#ifndef CG2D_OUTERLOOPITERS |
9 |
# define CG2D_OUTERLOOPITERS 10 |
10 |
#endif |
11 |
#endif /* TARGET_NEC_SX */ |
12 |
|
13 |
CBOP |
14 |
C !ROUTINE: CG2D |
15 |
C !INTERFACE: |
16 |
SUBROUTINE CG2D( |
17 |
I cg2d_b, |
18 |
U cg2d_x, |
19 |
O firstResidual, |
20 |
O lastResidual, |
21 |
U numIters, |
22 |
I myThid ) |
23 |
C !DESCRIPTION: \bv |
24 |
C *==========================================================* |
25 |
C | SUBROUTINE CG2D |
26 |
C | o Two-dimensional grid problem conjugate-gradient |
27 |
C | inverter (with preconditioner). |
28 |
C *==========================================================* |
29 |
C | Con. grad is an iterative procedure for solving Ax = b. |
30 |
C | It requires the A be symmetric. |
31 |
C | This implementation assumes A is a five-diagonal |
32 |
C | matrix of the form that arises in the discrete |
33 |
C | representation of the del^2 operator in a |
34 |
C | two-dimensional space. |
35 |
C | Notes: |
36 |
C | ====== |
37 |
C | This implementation can support shared-memory |
38 |
C | multi-threaded execution. In order to do this COMMON |
39 |
C | blocks are used for many of the arrays - even ones that |
40 |
C | are only used for intermedaite results. This design is |
41 |
C | OK if you want to all the threads to collaborate on |
42 |
C | solving the same problem. On the other hand if you want |
43 |
C | the threads to solve several different problems |
44 |
C | concurrently this implementation will not work. |
45 |
C *==========================================================* |
46 |
C \ev |
47 |
|
48 |
C !USES: |
49 |
IMPLICIT NONE |
50 |
C === Global data === |
51 |
#include "SIZE.h" |
52 |
#include "EEPARAMS.h" |
53 |
#include "PARAMS.h" |
54 |
#include "CG2D.h" |
55 |
c#include "GRID.h" |
56 |
c#include "SURFACE.h" |
57 |
|
58 |
C !INPUT/OUTPUT PARAMETERS: |
59 |
C === Routine arguments === |
60 |
C cg2d_b :: The source term or "right hand side" |
61 |
C cg2d_x :: The solution |
62 |
C firstResidual :: the initial residual before any iterations |
63 |
C lastResidual :: the actual residual reached |
64 |
C numIters :: Entry: the maximum number of iterations allowed |
65 |
C Exit: the actual number of iterations used |
66 |
C myThid :: Thread on which I am working. |
67 |
_RL cg2d_b(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
68 |
_RL cg2d_x(1-OLx:sNx+OLx,1-OLy:sNy+OLy,nSx,nSy) |
69 |
_RL firstResidual |
70 |
_RL lastResidual |
71 |
INTEGER numIters |
72 |
INTEGER myThid |
73 |
|
74 |
C !LOCAL VARIABLES: |
75 |
C === Local variables ==== |
76 |
C actualIts :: Number of iterations taken |
77 |
C actualResidual :: residual |
78 |
C bi, bj :: Block index in X and Y. |
79 |
C eta_qrN :: Used in computing search directions |
80 |
C eta_qrNM1 suffix N and NM1 denote current and |
81 |
C cgBeta previous iterations respectively. |
82 |
C alpha |
83 |
C sumRHS :: Sum of right-hand-side. Sometimes this is a |
84 |
C useful debuggin/trouble shooting diagnostic. |
85 |
C For neumann problems sumRHS needs to be ~0. |
86 |
C or they converge at a non-zero residual. |
87 |
C err :: Measure of residual of Ax - b, usually the norm. |
88 |
C I, J, it2d :: Loop counters ( it2d counts CG iterations ) |
89 |
INTEGER actualIts |
90 |
_RL actualResidual |
91 |
INTEGER bi, bj |
92 |
INTEGER I, J, it2d |
93 |
c INTEGER ks |
94 |
_RL err, errTile(nSx,nSy) |
95 |
_RL eta_qrN,eta_qrNtile(nSx,nSy) |
96 |
_RL eta_qrNM1 |
97 |
_RL cgBeta |
98 |
_RL alpha, alphaTile(nSx,nSy) |
99 |
_RL sumRHS, sumRHStile(nSx,nSy) |
100 |
_RL rhsMax |
101 |
_RL rhsNorm |
102 |
#ifdef CG2D_SINGLECPU_SUM |
103 |
_RL localBuf(1:sNx,1:sNy,nSx,nSy) |
104 |
#endif |
105 |
CHARACTER*(MAX_LEN_MBUF) msgBuf |
106 |
CEOP |
107 |
|
108 |
|
109 |
CcnhDebugStarts |
110 |
C CHARACTER*(MAX_LEN_FNAM) suff |
111 |
CcnhDebugEnds |
112 |
|
113 |
|
114 |
C-- Initialise inverter |
115 |
eta_qrNM1 = 1. _d 0 |
116 |
|
117 |
CcnhDebugStarts |
118 |
C _EXCH_XY_RL( cg2d_b, myThid ) |
119 |
C CALL PLOT_FIELD_XYRL( cg2d_b, 'CG2D.0 CG2D_B' , 1, myThid ) |
120 |
C suff = 'unnormalised' |
121 |
C CALL WRITE_FLD_XY_RL ( 'cg2d_b.',suff, cg2d_b, 1, myThid) |
122 |
C STOP |
123 |
CcnhDebugEnds |
124 |
|
125 |
C-- Normalise RHS |
126 |
rhsMax = 0. _d 0 |
127 |
DO bj=myByLo(myThid),myByHi(myThid) |
128 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
129 |
DO J=1,sNy |
130 |
DO I=1,sNx |
131 |
cg2d_b(I,J,bi,bj) = cg2d_b(I,J,bi,bj)*cg2dNorm |
132 |
rhsMax = MAX(ABS(cg2d_b(I,J,bi,bj)),rhsMax) |
133 |
ENDDO |
134 |
ENDDO |
135 |
ENDDO |
136 |
ENDDO |
137 |
|
138 |
IF (cg2dNormaliseRHS) THEN |
139 |
C- Normalise RHS : |
140 |
#ifdef LETS_MAKE_JAM |
141 |
C _GLOBAL_MAX_RL( rhsMax, myThid ) |
142 |
rhsMax=1. |
143 |
#else |
144 |
_GLOBAL_MAX_RL( rhsMax, myThid ) |
145 |
#endif |
146 |
rhsNorm = 1. _d 0 |
147 |
IF ( rhsMax .NE. 0. ) rhsNorm = 1. _d 0 / rhsMax |
148 |
DO bj=myByLo(myThid),myByHi(myThid) |
149 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
150 |
DO J=1,sNy |
151 |
DO I=1,sNx |
152 |
cg2d_b(I,J,bi,bj) = cg2d_b(I,J,bi,bj)*rhsNorm |
153 |
cg2d_x(I,J,bi,bj) = cg2d_x(I,J,bi,bj)*rhsNorm |
154 |
ENDDO |
155 |
ENDDO |
156 |
ENDDO |
157 |
ENDDO |
158 |
C- end Normalise RHS |
159 |
ENDIF |
160 |
|
161 |
C-- Update overlaps |
162 |
c CALL EXCH_XY_RL( cg2d_b, myThid ) |
163 |
CALL EXCH_XY_RL( cg2d_x, myThid ) |
164 |
CcnhDebugStarts |
165 |
C CALL PLOT_FIELD_XYRL( cg2d_b, 'CG2D.1 CG2D_B' , 1, myThid ) |
166 |
C suff = 'normalised' |
167 |
C CALL WRITE_FLD_XY_RL ( 'cg2d_b.',suff, cg2d_b, 1, myThid) |
168 |
CcnhDebugEnds |
169 |
|
170 |
C-- Initial residual calculation |
171 |
DO bj=myByLo(myThid),myByHi(myThid) |
172 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
173 |
DO J=1-1,sNy+1 |
174 |
DO I=1-1,sNx+1 |
175 |
cg2d_s(I,J,bi,bj) = 0. |
176 |
ENDDO |
177 |
ENDDO |
178 |
sumRHStile(bi,bj) = 0. _d 0 |
179 |
errTile(bi,bj) = 0. _d 0 |
180 |
#ifdef TARGET_NEC_SX |
181 |
!CDIR OUTERUNROLL=CG2D_OUTERLOOPITERS |
182 |
#endif /* TARGET_NEC_SX */ |
183 |
DO J=1,sNy |
184 |
DO I=1,sNx |
185 |
c ks = ksurfC(I,J,bi,bj) |
186 |
cg2d_r(I,J,bi,bj) = cg2d_b(I,J,bi,bj) - |
187 |
& (aW2d(I ,J ,bi,bj)*cg2d_x(I-1,J ,bi,bj) |
188 |
& +aW2d(I+1,J ,bi,bj)*cg2d_x(I+1,J ,bi,bj) |
189 |
& +aS2d(I ,J ,bi,bj)*cg2d_x(I ,J-1,bi,bj) |
190 |
& +aS2d(I ,J+1,bi,bj)*cg2d_x(I ,J+1,bi,bj) |
191 |
& +aC2d(I ,J ,bi,bj)*cg2d_x(I ,J ,bi,bj) |
192 |
& ) |
193 |
c & -aW2d(I ,J ,bi,bj)*cg2d_x(I ,J ,bi,bj) |
194 |
c & -aW2d(I+1,J ,bi,bj)*cg2d_x(I ,J ,bi,bj) |
195 |
c & -aS2d(I ,J ,bi,bj)*cg2d_x(I ,J ,bi,bj) |
196 |
c & -aS2d(I ,J+1,bi,bj)*cg2d_x(I ,J ,bi,bj) |
197 |
c & -freeSurfFac*_rA(i,j,bi,bj)*deepFac2F(ks)*recip_Bo(i,j,bi,bj) |
198 |
c & *cg2d_x(I ,J ,bi,bj) |
199 |
c & /deltaTMom/deltaTfreesurf*cg2dNorm |
200 |
c & ) |
201 |
#ifdef CG2D_SINGLECPU_SUM |
202 |
localBuf(I,J,bi,bj) = cg2d_r(I,J,bi,bj)*cg2d_r(I,J,bi,bj) |
203 |
#else |
204 |
errTile(bi,bj) = errTile(bi,bj) |
205 |
& + cg2d_r(I,J,bi,bj)*cg2d_r(I,J,bi,bj) |
206 |
sumRHStile(bi,bj) = sumRHStile(bi,bj) + cg2d_b(I,J,bi,bj) |
207 |
#endif |
208 |
ENDDO |
209 |
ENDDO |
210 |
ENDDO |
211 |
ENDDO |
212 |
CALL EXCH_S3D_RL( cg2d_r, 1, myThid ) |
213 |
#ifdef CG2D_SINGLECPU_SUM |
214 |
CALL GLOBAL_SUM_SINGLECPU_RL(localBuf, err, 0, 0, myThid) |
215 |
CALL GLOBAL_SUM_SINGLECPU_RL(cg2d_b, sumRHS, OLx, OLy, myThid) |
216 |
#else |
217 |
CALL GLOBAL_SUM_TILE_RL( errTile, err, myThid ) |
218 |
CALL GLOBAL_SUM_TILE_RL( sumRHStile, sumRHS, myThid ) |
219 |
#endif |
220 |
err = SQRT(err) |
221 |
actualIts = 0 |
222 |
actualResidual = err |
223 |
|
224 |
IF ( debugLevel .GE. debLevZero ) THEN |
225 |
_BEGIN_MASTER( myThid ) |
226 |
WRITE(standardmessageunit,'(A,1P2E22.14)') |
227 |
& ' cg2d: Sum(rhs),rhsMax = ', sumRHS,rhsMax |
228 |
_END_MASTER( myThid ) |
229 |
ENDIF |
230 |
C _BARRIER |
231 |
c _BEGIN_MASTER( myThid ) |
232 |
c WRITE(standardmessageunit,'(A,I6,1PE30.14)') |
233 |
c & ' CG2D iters, err = ', |
234 |
c & actualIts, actualResidual |
235 |
c _END_MASTER( myThid ) |
236 |
firstResidual=actualResidual |
237 |
|
238 |
IF ( err .LT. cg2dTolerance ) GOTO 11 |
239 |
|
240 |
C >>>>>>>>>>>>>>> BEGIN SOLVER <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< |
241 |
DO 10 it2d=1, numIters |
242 |
|
243 |
CcnhDebugStarts |
244 |
C WRITE(*,*) ' CG2D: Iteration ',it2d-1,' residual = ', |
245 |
C & actualResidual |
246 |
CcnhDebugEnds |
247 |
C-- Solve preconditioning equation and update |
248 |
C-- conjugate direction vector "s". |
249 |
DO bj=myByLo(myThid),myByHi(myThid) |
250 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
251 |
eta_qrNtile(bi,bj) = 0. _d 0 |
252 |
#ifdef TARGET_NEC_SX |
253 |
!CDIR OUTERUNROLL=CG2D_OUTERLOOPITERS |
254 |
#endif /* TARGET_NEC_SX */ |
255 |
DO J=1,sNy |
256 |
DO I=1,sNx |
257 |
cg2d_q(I,J,bi,bj) = |
258 |
& pC(I ,J ,bi,bj)*cg2d_r(I ,J ,bi,bj) |
259 |
& +pW(I ,J ,bi,bj)*cg2d_r(I-1,J ,bi,bj) |
260 |
& +pW(I+1,J ,bi,bj)*cg2d_r(I+1,J ,bi,bj) |
261 |
& +pS(I ,J ,bi,bj)*cg2d_r(I ,J-1,bi,bj) |
262 |
& +pS(I ,J+1,bi,bj)*cg2d_r(I ,J+1,bi,bj) |
263 |
CcnhDebugStarts |
264 |
C cg2d_q(I,J,bi,bj) = cg2d_r(I ,J ,bi,bj) |
265 |
CcnhDebugEnds |
266 |
#ifdef CG2D_SINGLECPU_SUM |
267 |
localBuf(I,J,bi,bj) = |
268 |
& cg2d_q(I,J,bi,bj)*cg2d_r(I,J,bi,bj) |
269 |
#else |
270 |
eta_qrNtile(bi,bj) = eta_qrNtile(bi,bj) |
271 |
& +cg2d_q(I,J,bi,bj)*cg2d_r(I,J,bi,bj) |
272 |
#endif |
273 |
ENDDO |
274 |
ENDDO |
275 |
ENDDO |
276 |
ENDDO |
277 |
|
278 |
#ifdef CG2D_SINGLECPU_SUM |
279 |
CALL GLOBAL_SUM_SINGLECPU_RL( localBuf,eta_qrN,0,0,myThid ) |
280 |
#else |
281 |
CALL GLOBAL_SUM_TILE_RL( eta_qrNtile,eta_qrN,myThid ) |
282 |
#endif |
283 |
CcnhDebugStarts |
284 |
C WRITE(*,*) ' CG2D: Iteration ',it2d-1,' eta_qrN = ',eta_qrN |
285 |
CcnhDebugEnds |
286 |
cgBeta = eta_qrN/eta_qrNM1 |
287 |
CcnhDebugStarts |
288 |
C WRITE(*,*) ' CG2D: Iteration ',it2d-1,' beta = ',cgBeta |
289 |
CcnhDebugEnds |
290 |
eta_qrNM1 = eta_qrN |
291 |
|
292 |
DO bj=myByLo(myThid),myByHi(myThid) |
293 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
294 |
DO J=1,sNy |
295 |
DO I=1,sNx |
296 |
cg2d_s(I,J,bi,bj) = cg2d_q(I,J,bi,bj) |
297 |
& + cgBeta*cg2d_s(I,J,bi,bj) |
298 |
ENDDO |
299 |
ENDDO |
300 |
ENDDO |
301 |
ENDDO |
302 |
|
303 |
C-- Do exchanges that require messages i.e. between |
304 |
C-- processes. |
305 |
CALL EXCH_S3D_RL( cg2d_s, 1, myThid ) |
306 |
|
307 |
C== Evaluate laplace operator on conjugate gradient vector |
308 |
C== q = A.s |
309 |
DO bj=myByLo(myThid),myByHi(myThid) |
310 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
311 |
alphaTile(bi,bj) = 0. _d 0 |
312 |
#ifdef TARGET_NEC_SX |
313 |
!CDIR OUTERUNROLL=CG2D_OUTERLOOPITERS |
314 |
#endif /* TARGET_NEC_SX */ |
315 |
DO J=1,sNy |
316 |
DO I=1,sNx |
317 |
c ks = ksurfC(I,J,bi,bj) |
318 |
cg2d_q(I,J,bi,bj) = |
319 |
& aW2d(I ,J ,bi,bj)*cg2d_s(I-1,J ,bi,bj) |
320 |
& +aW2d(I+1,J ,bi,bj)*cg2d_s(I+1,J ,bi,bj) |
321 |
& +aS2d(I ,J ,bi,bj)*cg2d_s(I ,J-1,bi,bj) |
322 |
& +aS2d(I ,J+1,bi,bj)*cg2d_s(I ,J+1,bi,bj) |
323 |
& +aC2d(I ,J ,bi,bj)*cg2d_s(I ,J ,bi,bj) |
324 |
c & -aW2d(I ,J ,bi,bj)*cg2d_s(I ,J ,bi,bj) |
325 |
c & -aW2d(I+1,J ,bi,bj)*cg2d_s(I ,J ,bi,bj) |
326 |
c & -aS2d(I ,J ,bi,bj)*cg2d_s(I ,J ,bi,bj) |
327 |
c & -aS2d(I ,J+1,bi,bj)*cg2d_s(I ,J ,bi,bj) |
328 |
c & -freeSurfFac*_rA(i,j,bi,bj)*deepFac2F(ks)*recip_Bo(i,j,bi,bj) |
329 |
c & *cg2d_s(I ,J ,bi,bj) |
330 |
c & /deltaTMom/deltaTfreesurf*cg2dNorm |
331 |
#ifdef CG2D_SINGLECPU_SUM |
332 |
localBuf(I,J,bi,bj) = cg2d_s(I,J,bi,bj)*cg2d_q(I,J,bi,bj) |
333 |
#else |
334 |
alphaTile(bi,bj) = alphaTile(bi,bj) |
335 |
& + cg2d_s(I,J,bi,bj)*cg2d_q(I,J,bi,bj) |
336 |
#endif |
337 |
ENDDO |
338 |
ENDDO |
339 |
ENDDO |
340 |
ENDDO |
341 |
#ifdef CG2D_SINGLECPU_SUM |
342 |
CALL GLOBAL_SUM_SINGLECPU_RL(localBuf, alpha, 0, 0, myThid) |
343 |
#else |
344 |
CALL GLOBAL_SUM_TILE_RL( alphaTile, alpha, myThid ) |
345 |
#endif |
346 |
CcnhDebugStarts |
347 |
C WRITE(*,*) ' CG2D: Iteration ',it2d-1,' SUM(s*q)= ',alpha |
348 |
CcnhDebugEnds |
349 |
alpha = eta_qrN/alpha |
350 |
CcnhDebugStarts |
351 |
C WRITE(*,*) ' CG2D: Iteration ',it2d-1,' alpha= ',alpha |
352 |
CcnhDebugEnds |
353 |
|
354 |
C== Update solution and residual vectors |
355 |
C Now compute "interior" points. |
356 |
DO bj=myByLo(myThid),myByHi(myThid) |
357 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
358 |
errTile(bi,bj) = 0. _d 0 |
359 |
DO J=1,sNy |
360 |
DO I=1,sNx |
361 |
cg2d_x(I,J,bi,bj)=cg2d_x(I,J,bi,bj)+alpha*cg2d_s(I,J,bi,bj) |
362 |
cg2d_r(I,J,bi,bj)=cg2d_r(I,J,bi,bj)-alpha*cg2d_q(I,J,bi,bj) |
363 |
#ifdef CG2D_SINGLECPU_SUM |
364 |
localBuf(I,J,bi,bj) = cg2d_r(I,J,bi,bj)*cg2d_r(I,J,bi,bj) |
365 |
#else |
366 |
errTile(bi,bj) = errTile(bi,bj) |
367 |
& + cg2d_r(I,J,bi,bj)*cg2d_r(I,J,bi,bj) |
368 |
#endif |
369 |
ENDDO |
370 |
ENDDO |
371 |
ENDDO |
372 |
ENDDO |
373 |
|
374 |
#ifdef CG2D_SINGLECPU_SUM |
375 |
CALL GLOBAL_SUM_SINGLECPU_RL(localBuf, err, 0, 0, myThid) |
376 |
#else |
377 |
CALL GLOBAL_SUM_TILE_RL( errTile, err, myThid ) |
378 |
#endif |
379 |
err = SQRT(err) |
380 |
actualIts = it2d |
381 |
actualResidual = err |
382 |
IF ( debugLevel.GT.debLevB ) THEN |
383 |
c IF ( DIFFERENT_MULTIPLE(monitorFreq,myTime,deltaTClock) |
384 |
c & ) THEN |
385 |
_BEGIN_MASTER( myThid ) |
386 |
WRITE(msgBuf,'(A,I6,A,1PE21.14)') |
387 |
& ' cg2d: iter=', actualIts, ' ; resid.= ', actualResidual |
388 |
CALL PRINT_MESSAGE(msgBuf,standardMessageUnit,SQUEEZE_RIGHT,1) |
389 |
_END_MASTER( myThid ) |
390 |
c ENDIF |
391 |
ENDIF |
392 |
IF ( err .LT. cg2dTolerance ) GOTO 11 |
393 |
|
394 |
CALL EXCH_S3D_RL( cg2d_r, 1, myThid ) |
395 |
|
396 |
10 CONTINUE |
397 |
11 CONTINUE |
398 |
|
399 |
IF (cg2dNormaliseRHS) THEN |
400 |
C-- Un-normalise the answer |
401 |
DO bj=myByLo(myThid),myByHi(myThid) |
402 |
DO bi=myBxLo(myThid),myBxHi(myThid) |
403 |
DO J=1,sNy |
404 |
DO I=1,sNx |
405 |
cg2d_x(I ,J ,bi,bj) = cg2d_x(I ,J ,bi,bj)/rhsNorm |
406 |
ENDDO |
407 |
ENDDO |
408 |
ENDDO |
409 |
ENDDO |
410 |
ENDIF |
411 |
|
412 |
C The following exchange was moved up to solve_for_pressure |
413 |
C for compatibility with TAMC. |
414 |
C _EXCH_XY_RL(cg2d_x, myThid ) |
415 |
c _BEGIN_MASTER( myThid ) |
416 |
c WRITE(*,'(A,I6,1PE30.14)') ' CG2D iters, err = ', |
417 |
c & actualIts, actualResidual |
418 |
c _END_MASTER( myThid ) |
419 |
|
420 |
C-- Return parameters to caller |
421 |
lastResidual=actualResidual |
422 |
numIters=actualIts |
423 |
|
424 |
CcnhDebugStarts |
425 |
C CALL PLOT_FIELD_XYRL( cg2d_x, 'CALC_MOM_RHS CG2D_X' , 1, myThid ) |
426 |
C err = 0. _d 0 |
427 |
C DO bj=myByLo(myThid),myByHi(myThid) |
428 |
C DO bi=myBxLo(myThid),myBxHi(myThid) |
429 |
C DO J=1,sNy |
430 |
C DO I=1,sNx |
431 |
C cg2d_r(I,J,bi,bj) = cg2d_b(I,J,bi,bj) - |
432 |
C & (aW2d(I ,J ,bi,bj)*cg2d_x(I-1,J ,bi,bj) |
433 |
C & +aW2d(I+1,J ,bi,bj)*cg2d_x(I+1,J ,bi,bj) |
434 |
C & +aS2d(I ,J ,bi,bj)*cg2d_x(I ,J-1,bi,bj) |
435 |
C & +aS2d(I ,J+1,bi,bj)*cg2d_x(I ,J+1,bi,bj) |
436 |
C & -aW2d(I ,J ,bi,bj)*cg2d_x(I ,J ,bi,bj) |
437 |
C & -aW2d(I+1,J ,bi,bj)*cg2d_x(I ,J ,bi,bj) |
438 |
C & -aS2d(I ,J ,bi,bj)*cg2d_x(I ,J ,bi,bj) |
439 |
C & -aS2d(I ,J+1,bi,bj)*cg2d_x(I ,J ,bi,bj)) |
440 |
C err = err + |
441 |
C & cg2d_r(I,J,bi,bj)*cg2d_r(I,J,bi,bj) |
442 |
C ENDDO |
443 |
C ENDDO |
444 |
C ENDDO |
445 |
C ENDDO |
446 |
C _GLOBAL_SUM_RL( err , myThid ) |
447 |
C write(*,*) 'cg2d: Ax - b = ',SQRT(err) |
448 |
CcnhDebugEnds |
449 |
|
450 |
RETURN |
451 |
END |