Actual source code: fftw.c


  2: /*
  3:     Provides an interface to the FFTW package.
  4:     Testing examples can be found in ~src/mat/tests
  5: */

  7: #include <../src/mat/impls/fft/fft.h>
  8: EXTERN_C_BEGIN
  9: #include <fftw3-mpi.h>
 10: EXTERN_C_END

 12: typedef struct {
 13:   ptrdiff_t    ndim_fftw,*dim_fftw;
 14: #if defined(PETSC_USE_64BIT_INDICES)
 15:   fftw_iodim64 *iodims;
 16: #else
 17:   fftw_iodim   *iodims;
 18: #endif
 19:   PetscInt     partial_dim;
 20:   fftw_plan    p_forward,p_backward;
 21:   unsigned     p_flag; /* planner flags, FFTW_ESTIMATE,FFTW_MEASURE, FFTW_PATIENT, FFTW_EXHAUSTIVE */
 22:   PetscScalar  *finarray,*foutarray,*binarray,*boutarray; /* keep track of arrays becaue fftw plan should be
 23:                                                             executed for the arrays with which the plan was created */
 24: } Mat_FFTW;

 26: extern PetscErrorCode MatMult_SeqFFTW(Mat,Vec,Vec);
 27: extern PetscErrorCode MatMultTranspose_SeqFFTW(Mat,Vec,Vec);
 28: extern PetscErrorCode MatMult_MPIFFTW(Mat,Vec,Vec);
 29: extern PetscErrorCode MatMultTranspose_MPIFFTW(Mat,Vec,Vec);
 30: extern PetscErrorCode MatDestroy_FFTW(Mat);
 31: extern PetscErrorCode VecDestroy_MPIFFTW(Vec);
 32: extern PetscErrorCode MatCreateVecsFFTW_FFTW(Mat,Vec*,Vec*,Vec*);

 34: /* MatMult_SeqFFTW performs forward DFT in parallel
 35:    Input parameter:
 36:      A - the matrix
 37:      x - the vector on which FDFT will be performed

 39:    Output parameter:
 40:      y - vector that stores result of FDFT
 41: */
 42: PetscErrorCode MatMult_SeqFFTW(Mat A,Vec x,Vec y)
 43: {
 45:   Mat_FFT        *fft  = (Mat_FFT*)A->data;
 46:   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
 47:   const PetscScalar *x_array;
 48:   PetscScalar    *y_array;
 49: #if defined(PETSC_USE_COMPLEX)
 50: #if defined(PETSC_USE_64BIT_INDICES)
 51:   fftw_iodim64   *iodims;
 52: #else
 53:   fftw_iodim     *iodims;
 54: #endif
 55:   PetscInt       i;
 56: #endif
 57:   PetscInt       ndim = fft->ndim,*dim = fft->dim;

 60:   VecGetArrayRead(x,&x_array);
 61:   VecGetArray(y,&y_array);
 62:   if (!fftw->p_forward) { /* create a plan, then excute it */
 63:     switch (ndim) {
 64:     case 1:
 65: #if defined(PETSC_USE_COMPLEX)
 66:       fftw->p_forward = fftw_plan_dft_1d(dim[0],(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_FORWARD,fftw->p_flag);
 67: #else
 68:       fftw->p_forward = fftw_plan_dft_r2c_1d(dim[0],(double*)x_array,(fftw_complex*)y_array,fftw->p_flag);
 69: #endif
 70:       break;
 71:     case 2:
 72: #if defined(PETSC_USE_COMPLEX)
 73:       fftw->p_forward = fftw_plan_dft_2d(dim[0],dim[1],(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_FORWARD,fftw->p_flag);
 74: #else
 75:       fftw->p_forward = fftw_plan_dft_r2c_2d(dim[0],dim[1],(double*)x_array,(fftw_complex*)y_array,fftw->p_flag);
 76: #endif
 77:       break;
 78:     case 3:
 79: #if defined(PETSC_USE_COMPLEX)
 80:       fftw->p_forward = fftw_plan_dft_3d(dim[0],dim[1],dim[2],(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_FORWARD,fftw->p_flag);
 81: #else
 82:       fftw->p_forward = fftw_plan_dft_r2c_3d(dim[0],dim[1],dim[2],(double*)x_array,(fftw_complex*)y_array,fftw->p_flag);
 83: #endif
 84:       break;
 85:     default:
 86: #if defined(PETSC_USE_COMPLEX)
 87:       iodims = fftw->iodims;
 88: #if defined(PETSC_USE_64BIT_INDICES)
 89:       if (ndim) {
 90:         iodims[ndim-1].n = (ptrdiff_t)dim[ndim-1];
 91:         iodims[ndim-1].is = iodims[ndim-1].os = 1;
 92:         for (i=ndim-2; i>=0; --i) {
 93:           iodims[i].n = (ptrdiff_t)dim[i];
 94:           iodims[i].is = iodims[i].os = iodims[i+1].is * iodims[i+1].n;
 95:         }
 96:       }
 97:       fftw->p_forward = fftw_plan_guru64_dft((int)ndim,(fftw_iodim64*)iodims,0,NULL,(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_FORWARD,fftw->p_flag);
 98: #else
 99:       if (ndim) {
100:         iodims[ndim-1].n = (int)dim[ndim-1];
101:         iodims[ndim-1].is = iodims[ndim-1].os = 1;
102:         for (i=ndim-2; i>=0; --i) {
103:           iodims[i].n = (int)dim[i];
104:           iodims[i].is = iodims[i].os = iodims[i+1].is * iodims[i+1].n;
105:         }
106:       }
107:       fftw->p_forward = fftw_plan_guru_dft((int)ndim,(fftw_iodim*)iodims,0,NULL,(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_FORWARD,fftw->p_flag);
108: #endif

110: #else
111:       fftw->p_forward = fftw_plan_dft_r2c(ndim,(int*)dim,(double*)x_array,(fftw_complex*)y_array,fftw->p_flag);
112: #endif
113:       break;
114:     }
115:     fftw->finarray  = (PetscScalar *) x_array;
116:     fftw->foutarray = y_array;
117:     /* Warning: if (fftw->p_flag!==FFTW_ESTIMATE) The data in the in/out arrays is overwritten!
118:                 planning should be done before x is initialized! See FFTW manual sec2.1 or sec4 */
119:     fftw_execute(fftw->p_forward);
120:   } else { /* use existing plan */
121:     if (fftw->finarray != x_array || fftw->foutarray != y_array) { /* use existing plan on new arrays */
122: #if defined(PETSC_USE_COMPLEX)
123:       fftw_execute_dft(fftw->p_forward,(fftw_complex*)x_array,(fftw_complex*)y_array);
124: #else
125:       fftw_execute_dft_r2c(fftw->p_forward,(double*)x_array,(fftw_complex*)y_array);
126: #endif
127:     } else {
128:       fftw_execute(fftw->p_forward);
129:     }
130:   }
131:   VecRestoreArray(y,&y_array);
132:   VecRestoreArrayRead(x,&x_array);
133:   return(0);
134: }

136: /* MatMultTranspose_SeqFFTW performs serial backward DFT
137:    Input parameter:
138:      A - the matrix
139:      x - the vector on which BDFT will be performed

141:    Output parameter:
142:      y - vector that stores result of BDFT
143: */

145: PetscErrorCode MatMultTranspose_SeqFFTW(Mat A,Vec x,Vec y)
146: {
148:   Mat_FFT        *fft  = (Mat_FFT*)A->data;
149:   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
150:   const PetscScalar *x_array;
151:   PetscScalar    *y_array;
152:   PetscInt       ndim=fft->ndim,*dim=fft->dim;
153: #if defined(PETSC_USE_COMPLEX)
154: #if defined(PETSC_USE_64BIT_INDICES)
155:   fftw_iodim64   *iodims=fftw->iodims;
156: #else
157:   fftw_iodim     *iodims=fftw->iodims;
158: #endif
159: #endif

162:   VecGetArrayRead(x,&x_array);
163:   VecGetArray(y,&y_array);
164:   if (!fftw->p_backward) { /* create a plan, then excute it */
165:     switch (ndim) {
166:     case 1:
167: #if defined(PETSC_USE_COMPLEX)
168:       fftw->p_backward = fftw_plan_dft_1d(dim[0],(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_BACKWARD,fftw->p_flag);
169: #else
170:       fftw->p_backward= fftw_plan_dft_c2r_1d(dim[0],(fftw_complex*)x_array,(double*)y_array,fftw->p_flag);
171: #endif
172:       break;
173:     case 2:
174: #if defined(PETSC_USE_COMPLEX)
175:       fftw->p_backward = fftw_plan_dft_2d(dim[0],dim[1],(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_BACKWARD,fftw->p_flag);
176: #else
177:       fftw->p_backward= fftw_plan_dft_c2r_2d(dim[0],dim[1],(fftw_complex*)x_array,(double*)y_array,fftw->p_flag);
178: #endif
179:       break;
180:     case 3:
181: #if defined(PETSC_USE_COMPLEX)
182:       fftw->p_backward = fftw_plan_dft_3d(dim[0],dim[1],dim[2],(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_BACKWARD,fftw->p_flag);
183: #else
184:       fftw->p_backward= fftw_plan_dft_c2r_3d(dim[0],dim[1],dim[2],(fftw_complex*)x_array,(double*)y_array,fftw->p_flag);
185: #endif
186:       break;
187:     default:
188: #if defined(PETSC_USE_COMPLEX)
189: #if defined(PETSC_USE_64BIT_INDICES)
190:       fftw->p_backward = fftw_plan_guru64_dft((int)ndim,(fftw_iodim64*)iodims,0,NULL,(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_BACKWARD,fftw->p_flag);
191: #else
192:       fftw->p_backward = fftw_plan_guru_dft((int)ndim,iodims,0,NULL,(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_BACKWARD,fftw->p_flag);
193: #endif
194: #else
195:       fftw->p_backward= fftw_plan_dft_c2r((int)ndim,(int*)dim,(fftw_complex*)x_array,(double*)y_array,fftw->p_flag);
196: #endif
197:       break;
198:     }
199:     fftw->binarray  = (PetscScalar *) x_array;
200:     fftw->boutarray = y_array;
201:     fftw_execute(fftw->p_backward);
202:   } else { /* use existing plan */
203:     if (fftw->binarray != x_array || fftw->boutarray != y_array) { /* use existing plan on new arrays */
204: #if defined(PETSC_USE_COMPLEX)
205:       fftw_execute_dft(fftw->p_backward,(fftw_complex*)x_array,(fftw_complex*)y_array);
206: #else
207:       fftw_execute_dft_c2r(fftw->p_backward,(fftw_complex*)x_array,(double*)y_array);
208: #endif
209:     } else {
210:       fftw_execute(fftw->p_backward);
211:     }
212:   }
213:   VecRestoreArray(y,&y_array);
214:   VecRestoreArrayRead(x,&x_array);
215:   return(0);
216: }

218: /* MatMult_MPIFFTW performs forward DFT in parallel
219:    Input parameter:
220:      A - the matrix
221:      x - the vector on which FDFT will be performed

223:    Output parameter:
224:    y   - vector that stores result of FDFT
225: */
226: PetscErrorCode MatMult_MPIFFTW(Mat A,Vec x,Vec y)
227: {
229:   Mat_FFT        *fft  = (Mat_FFT*)A->data;
230:   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
231:   const PetscScalar *x_array;
232:   PetscScalar    *y_array;
233:   PetscInt       ndim=fft->ndim,*dim=fft->dim;
234:   MPI_Comm       comm;

237:   PetscObjectGetComm((PetscObject)A,&comm);
238:   VecGetArrayRead(x,&x_array);
239:   VecGetArray(y,&y_array);
240:   if (!fftw->p_forward) { /* create a plan, then excute it */
241:     switch (ndim) {
242:     case 1:
243: #if defined(PETSC_USE_COMPLEX)
244:       fftw->p_forward = fftw_mpi_plan_dft_1d(dim[0],(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_FORWARD,fftw->p_flag);
245: #else
246:       SETERRQ(comm,PETSC_ERR_SUP,"not support for real numbers yet");
247: #endif
248:       break;
249:     case 2:
250: #if defined(PETSC_USE_COMPLEX) /* For complex transforms call fftw_mpi_plan_dft, for real transforms call fftw_mpi_plan_dft_r2c */
251:       fftw->p_forward = fftw_mpi_plan_dft_2d(dim[0],dim[1],(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_FORWARD,fftw->p_flag);
252: #else
253:       fftw->p_forward = fftw_mpi_plan_dft_r2c_2d(dim[0],dim[1],(double*)x_array,(fftw_complex*)y_array,comm,FFTW_ESTIMATE);
254: #endif
255:       break;
256:     case 3:
257: #if defined(PETSC_USE_COMPLEX)
258:       fftw->p_forward = fftw_mpi_plan_dft_3d(dim[0],dim[1],dim[2],(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_FORWARD,fftw->p_flag);
259: #else
260:       fftw->p_forward = fftw_mpi_plan_dft_r2c_3d(dim[0],dim[1],dim[2],(double*)x_array,(fftw_complex*)y_array,comm,FFTW_ESTIMATE);
261: #endif
262:       break;
263:     default:
264: #if defined(PETSC_USE_COMPLEX)
265:       fftw->p_forward = fftw_mpi_plan_dft(fftw->ndim_fftw,fftw->dim_fftw,(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_FORWARD,fftw->p_flag);
266: #else
267:       fftw->p_forward = fftw_mpi_plan_dft_r2c(fftw->ndim_fftw,fftw->dim_fftw,(double*)x_array,(fftw_complex*)y_array,comm,FFTW_ESTIMATE);
268: #endif
269:       break;
270:     }
271:     fftw->finarray  = (PetscScalar *) x_array;
272:     fftw->foutarray = y_array;
273:     /* Warning: if (fftw->p_flag!==FFTW_ESTIMATE) The data in the in/out arrays is overwritten!
274:                 planning should be done before x is initialized! See FFTW manual sec2.1 or sec4 */
275:     fftw_execute(fftw->p_forward);
276:   } else { /* use existing plan */
277:     if (fftw->finarray != x_array || fftw->foutarray != y_array) { /* use existing plan on new arrays */
278:       fftw_execute_dft(fftw->p_forward,(fftw_complex*)x_array,(fftw_complex*)y_array);
279:     } else {
280:       fftw_execute(fftw->p_forward);
281:     }
282:   }
283:   VecRestoreArray(y,&y_array);
284:   VecRestoreArrayRead(x,&x_array);
285:   return(0);
286: }

288: /* MatMultTranspose_MPIFFTW performs parallel backward DFT
289:    Input parameter:
290:      A - the matrix
291:      x - the vector on which BDFT will be performed

293:    Output parameter:
294:      y - vector that stores result of BDFT
295: */
296: PetscErrorCode MatMultTranspose_MPIFFTW(Mat A,Vec x,Vec y)
297: {
299:   Mat_FFT        *fft  = (Mat_FFT*)A->data;
300:   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
301:   const PetscScalar *x_array;
302:   PetscScalar    *y_array;
303:   PetscInt       ndim=fft->ndim,*dim=fft->dim;
304:   MPI_Comm       comm;

307:   PetscObjectGetComm((PetscObject)A,&comm);
308:   VecGetArrayRead(x,&x_array);
309:   VecGetArray(y,&y_array);
310:   if (!fftw->p_backward) { /* create a plan, then excute it */
311:     switch (ndim) {
312:     case 1:
313: #if defined(PETSC_USE_COMPLEX)
314:       fftw->p_backward = fftw_mpi_plan_dft_1d(dim[0],(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_BACKWARD,fftw->p_flag);
315: #else
316:       SETERRQ(comm,PETSC_ERR_SUP,"not support for real numbers yet");
317: #endif
318:       break;
319:     case 2:
320: #if defined(PETSC_USE_COMPLEX) /* For complex transforms call fftw_mpi_plan_dft with flag FFTW_BACKWARD, for real transforms call fftw_mpi_plan_dft_c2r */
321:       fftw->p_backward = fftw_mpi_plan_dft_2d(dim[0],dim[1],(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_BACKWARD,fftw->p_flag);
322: #else
323:       fftw->p_backward = fftw_mpi_plan_dft_c2r_2d(dim[0],dim[1],(fftw_complex*)x_array,(double*)y_array,comm,FFTW_ESTIMATE);
324: #endif
325:       break;
326:     case 3:
327: #if defined(PETSC_USE_COMPLEX)
328:       fftw->p_backward = fftw_mpi_plan_dft_3d(dim[0],dim[1],dim[2],(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_BACKWARD,fftw->p_flag);
329: #else
330:       fftw->p_backward = fftw_mpi_plan_dft_c2r_3d(dim[0],dim[1],dim[2],(fftw_complex*)x_array,(double*)y_array,comm,FFTW_ESTIMATE);
331: #endif
332:       break;
333:     default:
334: #if defined(PETSC_USE_COMPLEX)
335:       fftw->p_backward = fftw_mpi_plan_dft(fftw->ndim_fftw,fftw->dim_fftw,(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_BACKWARD,fftw->p_flag);
336: #else
337:       fftw->p_backward = fftw_mpi_plan_dft_c2r(fftw->ndim_fftw,fftw->dim_fftw,(fftw_complex*)x_array,(double*)y_array,comm,FFTW_ESTIMATE);
338: #endif
339:       break;
340:     }
341:     fftw->binarray  = (PetscScalar *) x_array;
342:     fftw->boutarray = y_array;
343:     fftw_execute(fftw->p_backward);
344:   } else { /* use existing plan */
345:     if (fftw->binarray != x_array || fftw->boutarray != y_array) { /* use existing plan on new arrays */
346:       fftw_execute_dft(fftw->p_backward,(fftw_complex*)x_array,(fftw_complex*)y_array);
347:     } else {
348:       fftw_execute(fftw->p_backward);
349:     }
350:   }
351:   VecRestoreArray(y,&y_array);
352:   VecRestoreArrayRead(x,&x_array);
353:   return(0);
354: }

356: PetscErrorCode MatDestroy_FFTW(Mat A)
357: {
358:   Mat_FFT        *fft  = (Mat_FFT*)A->data;
359:   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;

363:   fftw_destroy_plan(fftw->p_forward);
364:   fftw_destroy_plan(fftw->p_backward);
365:   if (fftw->iodims) {
366:     free(fftw->iodims);
367:   }
368:   PetscFree(fftw->dim_fftw);
369:   PetscFree(fft->data);
370:   fftw_mpi_cleanup();
371:   return(0);
372: }

374: #include <../src/vec/vec/impls/mpi/pvecimpl.h>
375: PetscErrorCode VecDestroy_MPIFFTW(Vec v)
376: {
378:   PetscScalar    *array;

381:   VecGetArray(v,&array);
382:   fftw_free((fftw_complex*)array);
383:   VecRestoreArray(v,&array);
384:   VecDestroy_MPI(v);
385:   return(0);
386: }

388: static PetscErrorCode VecDuplicate_FFTW_fin(Vec fin,Vec *fin_new)
389: {
391:   Mat            A;

394:   PetscObjectQuery((PetscObject)fin,"FFTmatrix",(PetscObject*)&A);
395:   MatCreateVecsFFTW_FFTW(A,fin_new,NULL,NULL);
396:   return(0);
397: }

399: static PetscErrorCode VecDuplicate_FFTW_fout(Vec fout,Vec *fout_new)
400: {
402:   Mat            A;

405:   PetscObjectQuery((PetscObject)fout,"FFTmatrix",(PetscObject*)&A);
406:   MatCreateVecsFFTW_FFTW(A,NULL,fout_new,NULL);
407:   return(0);
408: }

410: static PetscErrorCode VecDuplicate_FFTW_bout(Vec bout, Vec *bout_new)
411: {
413:   Mat            A;

416:   PetscObjectQuery((PetscObject)bout,"FFTmatrix",(PetscObject*)&A);
417:   MatCreateVecsFFTW_FFTW(A,NULL,NULL,bout_new);
418:   return(0);
419: }

421: /*@
422:    MatCreateVecsFFTW - Get vector(s) compatible with the matrix, i.e. with the
423:      parallel layout determined by FFTW

425:    Collective on Mat

427:    Input Parameter:
428: .   A - the matrix

430:    Output Parameters:
431: +   x - (optional) input vector of forward FFTW
432: .   y - (optional) output vector of forward FFTW
433: -   z - (optional) output vector of backward FFTW

435:   Level: advanced

437:   Note: The parallel layout of output of forward FFTW is always same as the input
438:         of the backward FFTW. But parallel layout of the input vector of forward
439:         FFTW might not be same as the output of backward FFTW.
440:         Also note that we need to provide enough space while doing parallel real transform.
441:         We need to pad extra zeros at the end of last dimension. For this reason the one needs to
442:         invoke the routine fftw_mpi_local_size_transposed routines. Remember one has to change the
443:         last dimension from n to n/2+1 while invoking this routine. The number of zeros to be padded
444:         depends on if the last dimension is even or odd. If the last dimension is even need to pad two
445:         zeros if it is odd only one zero is needed.
446:         Lastly one needs some scratch space at the end of data set in each process. alloc_local
447:         figures out how much space is needed, i.e. it figures out the data+scratch space for
448:         each processor and returns that.

450: .seealso: MatCreateFFT()
451: @*/
452: PetscErrorCode MatCreateVecsFFTW(Mat A,Vec *x,Vec *y,Vec *z)
453: {

457:   PetscUseMethod(A,"MatCreateVecsFFTW_C",(Mat,Vec*,Vec*,Vec*),(A,x,y,z));
458:   return(0);
459: }

461: PetscErrorCode  MatCreateVecsFFTW_FFTW(Mat A,Vec *fin,Vec *fout,Vec *bout)
462: {
464:   PetscMPIInt    size,rank;
465:   MPI_Comm       comm;
466:   Mat_FFT        *fft  = (Mat_FFT*)A->data;
467:   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
468:   PetscInt       N     = fft->N;
469:   PetscInt       ndim  = fft->ndim,*dim=fft->dim,n=fft->n;

474:   PetscObjectGetComm((PetscObject)A,&comm);

476:   MPI_Comm_size(comm, &size);
477:   MPI_Comm_rank(comm, &rank);
478:   if (size == 1) { /* sequential case */
479: #if defined(PETSC_USE_COMPLEX)
480:     if (fin)  {VecCreateSeq(PETSC_COMM_SELF,N,fin);}
481:     if (fout) {VecCreateSeq(PETSC_COMM_SELF,N,fout);}
482:     if (bout) {VecCreateSeq(PETSC_COMM_SELF,N,bout);}
483: #else
484:     if (fin) {VecCreateSeq(PETSC_COMM_SELF,n,fin);}
485:     if (fout) {VecCreateSeq(PETSC_COMM_SELF,n,fout);}
486:     if (bout) {VecCreateSeq(PETSC_COMM_SELF,n,bout);}
487: #endif
488:   } else { /* parallel cases */
489:     ptrdiff_t    alloc_local,local_n0,local_0_start;
490:     ptrdiff_t    local_n1;
491:     fftw_complex *data_fout;
492:     ptrdiff_t    local_1_start;
493: #if defined(PETSC_USE_COMPLEX)
494:     fftw_complex *data_fin,*data_bout;
495: #else
496:     double    *data_finr,*data_boutr;
497:     PetscInt  n1,N1;
498:     ptrdiff_t temp;
499: #endif

501:     switch (ndim) {
502:     case 1:
503: #if !defined(PETSC_USE_COMPLEX)
504:       SETERRQ(comm,PETSC_ERR_SUP,"FFTW does not allow parallel real 1D transform");
505: #else
506:       alloc_local = fftw_mpi_local_size_1d(dim[0],comm,FFTW_FORWARD,FFTW_ESTIMATE,&local_n0,&local_0_start,&local_n1,&local_1_start);
507:       if (fin) {
508:         data_fin  = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
509:         VecCreateMPIWithArray(comm,1,local_n0,N,(const PetscScalar*)data_fin,fin);
510:         PetscObjectCompose((PetscObject)*fin,"FFTmatrix",(PetscObject)A);
511:         (*fin)->ops->duplicate = VecDuplicate_FFTW_fin;
512:         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
513:       }
514:       if (fout) {
515:         data_fout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
516:         VecCreateMPIWithArray(comm,1,local_n1,N,(const PetscScalar*)data_fout,fout);
517:         PetscObjectCompose((PetscObject)*fout,"FFTmatrix",(PetscObject)A);
518:         (*fout)->ops->duplicate = VecDuplicate_FFTW_fout;
519:         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
520:       }
521:       alloc_local = fftw_mpi_local_size_1d(dim[0],comm,FFTW_BACKWARD,FFTW_ESTIMATE,&local_n0,&local_0_start,&local_n1,&local_1_start);
522:       if (bout) {
523:         data_bout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
524:         VecCreateMPIWithArray(comm,1,local_n1,N,(const PetscScalar*)data_bout,bout);
525:         PetscObjectCompose((PetscObject)*bout,"FFTmatrix",(PetscObject)A);
526:         (*bout)->ops->duplicate = VecDuplicate_FFTW_fout;
527:         (*bout)->ops->destroy   = VecDestroy_MPIFFTW;
528:       }
529:       break;
530: #endif
531:     case 2:
532: #if !defined(PETSC_USE_COMPLEX) /* Note that N1 is no more the product of individual dimensions */
533:       alloc_local =  fftw_mpi_local_size_2d_transposed(dim[0],dim[1]/2+1,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);
534:       N1          = 2*dim[0]*(dim[1]/2+1); n1 = 2*local_n0*(dim[1]/2+1);
535:       if (fin) {
536:         data_finr = (double*)fftw_malloc(sizeof(double)*alloc_local*2);
537:         VecCreateMPIWithArray(comm,1,(PetscInt)n1,N1,(PetscScalar*)data_finr,fin);
538:         PetscObjectCompose((PetscObject)*fin,"FFTmatrix",(PetscObject)A);
539:         (*fin)->ops->duplicate = VecDuplicate_FFTW_fin;
540:         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
541:       }
542:       if (fout) {
543:         data_fout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
544:         VecCreateMPIWithArray(comm,1,(PetscInt)n1,N1,(PetscScalar*)data_fout,fout);
545:         PetscObjectCompose((PetscObject)*fout,"FFTmatrix",(PetscObject)A);
546:         (*fout)->ops->duplicate = VecDuplicate_FFTW_fout;
547:         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
548:       }
549:       if (bout) {
550:         data_boutr = (double*)fftw_malloc(sizeof(double)*alloc_local*2);
551:         VecCreateMPIWithArray(comm,1,(PetscInt)n1,N1,(PetscScalar*)data_boutr,bout);
552:         PetscObjectCompose((PetscObject)*bout,"FFTmatrix",(PetscObject)A);
553:         (*bout)->ops->duplicate = VecDuplicate_FFTW_bout;
554:         (*bout)->ops->destroy   = VecDestroy_MPIFFTW;
555:       }
556: #else
557:       /* Get local size */
558:       alloc_local = fftw_mpi_local_size_2d(dim[0],dim[1],comm,&local_n0,&local_0_start);
559:       if (fin) {
560:         data_fin = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
561:         VecCreateMPIWithArray(comm,1,n,N,(const PetscScalar*)data_fin,fin);
562:         PetscObjectCompose((PetscObject)*fin,"FFTmatrix",(PetscObject)A);
563:         (*fin)->ops->duplicate = VecDuplicate_FFTW_fin;
564:         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
565:       }
566:       if (fout) {
567:         data_fout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
568:         VecCreateMPIWithArray(comm,1,n,N,(const PetscScalar*)data_fout,fout);
569:         PetscObjectCompose((PetscObject)*fout,"FFTmatrix",(PetscObject)A);
570:         (*fout)->ops->duplicate = VecDuplicate_FFTW_fout;
571:         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
572:       }
573:       if (bout) {
574:         data_bout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
575:         VecCreateMPIWithArray(comm,1,n,N,(const PetscScalar*)data_bout,bout);
576:         PetscObjectCompose((PetscObject)*bout,"FFTmatrix",(PetscObject)A);
577:         (*bout)->ops->duplicate = VecDuplicate_FFTW_bout;
578:         (*bout)->ops->destroy   = VecDestroy_MPIFFTW;
579:       }
580: #endif
581:       break;
582:     case 3:
583: #if !defined(PETSC_USE_COMPLEX)
584:       alloc_local =  fftw_mpi_local_size_3d_transposed(dim[0],dim[1],dim[2]/2+1,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);
585:       N1 = 2*dim[0]*dim[1]*(dim[2]/2+1); n1 = 2*local_n0*dim[1]*(dim[2]/2+1);
586:       if (fin) {
587:         data_finr = (double*)fftw_malloc(sizeof(double)*alloc_local*2);
588:         VecCreateMPIWithArray(comm,1,(PetscInt)n1,N1,(PetscScalar*)data_finr,fin);
589:         PetscObjectCompose((PetscObject)*fin,"FFTmatrix",(PetscObject)A);
590:         (*fin)->ops->duplicate = VecDuplicate_FFTW_fin;
591:         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
592:       }
593:       if (fout) {
594:         data_fout=(fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
595:         VecCreateMPIWithArray(comm,1,n1,N1,(PetscScalar*)data_fout,fout);
596:         PetscObjectCompose((PetscObject)*fout,"FFTmatrix",(PetscObject)A);
597:         (*fout)->ops->duplicate = VecDuplicate_FFTW_fout;
598:         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
599:       }
600:       if (bout) {
601:         data_boutr=(double*)fftw_malloc(sizeof(double)*alloc_local*2);
602:         VecCreateMPIWithArray(comm,1,(PetscInt)n1,N1,(PetscScalar*)data_boutr,bout);
603:         PetscObjectCompose((PetscObject)*bout,"FFTmatrix",(PetscObject)A);
604:         (*bout)->ops->duplicate = VecDuplicate_FFTW_bout;
605:         (*bout)->ops->destroy   = VecDestroy_MPIFFTW;
606:       }
607: #else
608:       alloc_local = fftw_mpi_local_size_3d(dim[0],dim[1],dim[2],comm,&local_n0,&local_0_start);
609:       if (fin) {
610:         data_fin  = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
611:         VecCreateMPIWithArray(comm,1,n,N,(const PetscScalar*)data_fin,fin);
612:         PetscObjectCompose((PetscObject)*fin,"FFTmatrix",(PetscObject)A);
613:         (*fin)->ops->duplicate = VecDuplicate_FFTW_fin;
614:         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
615:       }
616:       if (fout) {
617:         data_fout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
618:         VecCreateMPIWithArray(comm,1,n,N,(const PetscScalar*)data_fout,fout);
619:         PetscObjectCompose((PetscObject)*fout,"FFTmatrix",(PetscObject)A);
620:         (*fout)->ops->duplicate = VecDuplicate_FFTW_fout;
621:         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
622:       }
623:       if (bout) {
624:         data_bout  = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
625:         VecCreateMPIWithArray(comm,1,n,N,(const PetscScalar*)data_bout,bout);
626:         PetscObjectCompose((PetscObject)*bout,"FFTmatrix",(PetscObject)A);
627:         (*bout)->ops->duplicate = VecDuplicate_FFTW_bout;
628:         (*bout)->ops->destroy   = VecDestroy_MPIFFTW;
629:       }
630: #endif
631:       break;
632:     default:
633: #if !defined(PETSC_USE_COMPLEX)
634:       temp = (fftw->dim_fftw)[fftw->ndim_fftw-1];

636:       (fftw->dim_fftw)[fftw->ndim_fftw-1] = temp/2 + 1;

638:       alloc_local = fftw_mpi_local_size_transposed(fftw->ndim_fftw,fftw->dim_fftw,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);
639:       N1          = 2*N*(PetscInt)((fftw->dim_fftw)[fftw->ndim_fftw-1])/((PetscInt) temp);

641:       (fftw->dim_fftw)[fftw->ndim_fftw-1] = temp;

643:       if (fin) {
644:         data_finr=(double*)fftw_malloc(sizeof(double)*alloc_local*2);
645:         VecCreateMPIWithArray(comm,1,(PetscInt)n,N1,(PetscScalar*)data_finr,fin);
646:         PetscObjectCompose((PetscObject)*fin,"FFTmatrix",(PetscObject)A);
647:         (*fin)->ops->duplicate = VecDuplicate_FFTW_fin;
648:         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
649:       }
650:       if (fout) {
651:         data_fout=(fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
652:         VecCreateMPIWithArray(comm,1,n,N1,(PetscScalar*)data_fout,fout);
653:         PetscObjectCompose((PetscObject)*fout,"FFTmatrix",(PetscObject)A);
654:         (*fout)->ops->duplicate = VecDuplicate_FFTW_fout;
655:         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
656:       }
657:       if (bout) {
658:         data_boutr=(double*)fftw_malloc(sizeof(double)*alloc_local*2);
659:         VecCreateMPIWithArray(comm,1,(PetscInt)n,N1,(PetscScalar*)data_boutr,bout);
660:         PetscObjectCompose((PetscObject)*bout,"FFTmatrix",(PetscObject)A);
661:         (*bout)->ops->duplicate = VecDuplicate_FFTW_bout;
662:         (*bout)->ops->destroy   = VecDestroy_MPIFFTW;
663:       }
664: #else
665:       alloc_local = fftw_mpi_local_size(fftw->ndim_fftw,fftw->dim_fftw,comm,&local_n0,&local_0_start);
666:       if (fin) {
667:         data_fin  = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
668:         VecCreateMPIWithArray(comm,1,n,N,(const PetscScalar*)data_fin,fin);
669:         PetscObjectCompose((PetscObject)*fin,"FFTmatrix",(PetscObject)A);
670:         (*fin)->ops->duplicate = VecDuplicate_FFTW_fin;
671:         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
672:       }
673:       if (fout) {
674:         data_fout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
675:         VecCreateMPIWithArray(comm,1,n,N,(const PetscScalar*)data_fout,fout);
676:         PetscObjectCompose((PetscObject)*fout,"FFTmatrix",(PetscObject)A);
677:         (*fout)->ops->duplicate = VecDuplicate_FFTW_fout;
678:         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
679:       }
680:       if (bout) {
681:         data_bout  = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
682:         VecCreateMPIWithArray(comm,1,n,N,(const PetscScalar*)data_bout,bout);
683:         PetscObjectCompose((PetscObject)*bout,"FFTmatrix",(PetscObject)A);
684:         (*bout)->ops->duplicate = VecDuplicate_FFTW_bout;
685:         (*bout)->ops->destroy   = VecDestroy_MPIFFTW;
686:       }
687: #endif
688:       break;
689:     }
690:     /* fftw vectors have their data array allocated by fftw_malloc, such that v->array=xxx but
691:        v->array_allocated=NULL. A regular replacearray call won't free the memory and only causes
692:        memory leaks. We void these pointers here to avoid acident uses.
693:      */
694:     if (fin)  (*fin)->ops->replacearray = NULL;
695:     if (fout) (*fout)->ops->replacearray = NULL;
696:     if (bout) (*bout)->ops->replacearray = NULL;
697:   }
698:   return(0);
699: }

701: /*@
702:    VecScatterPetscToFFTW - Copies the PETSc vector to the vector that goes into FFTW block.

704:    Collective on Mat

706:    Input Parameters:
707: +  A - FFTW matrix
708: -  x - the PETSc vector

710:    Output Parameters:
711: .  y - the FFTW vector

713:   Options Database Keys:
714: . -mat_fftw_plannerflags - set FFTW planner flags

716:    Level: intermediate

718:    Note: For real parallel FFT, FFTW requires insertion of extra space at the end of last dimension. This required even when
719:          one is not doing in-place transform. The last dimension size must be changed to 2*(dim[last]/2+1) to accommodate these extra
720:          zeros. This routine does that job by scattering operation.

722: .seealso: VecScatterFFTWToPetsc()
723: @*/
724: PetscErrorCode VecScatterPetscToFFTW(Mat A,Vec x,Vec y)
725: {

729:   PetscUseMethod(A,"VecScatterPetscToFFTW_C",(Mat,Vec,Vec),(A,x,y));
730:   return(0);
731: }

733: PetscErrorCode VecScatterPetscToFFTW_FFTW(Mat A,Vec x,Vec y)
734: {
736:   MPI_Comm       comm;
737:   Mat_FFT        *fft  = (Mat_FFT*)A->data;
738:   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
739:   PetscInt       N     =fft->N;
740:   PetscInt       ndim  =fft->ndim,*dim=fft->dim;
741:   PetscInt       low;
742:   PetscMPIInt    rank,size;
743:   PetscInt       vsize,vsize1;
744:   ptrdiff_t      local_n0,local_0_start;
745:   ptrdiff_t      local_n1,local_1_start;
746:   VecScatter     vecscat;
747:   IS             list1,list2;
748: #if !defined(PETSC_USE_COMPLEX)
749:   PetscInt       i,j,k,partial_dim;
750:   PetscInt       *indx1, *indx2, tempindx, tempindx1;
751:   PetscInt       NM;
752:   ptrdiff_t      temp;
753: #endif

756:   PetscObjectGetComm((PetscObject)A,&comm);
757:   MPI_Comm_size(comm, &size);
758:   MPI_Comm_rank(comm, &rank);
759:   VecGetOwnershipRange(y,&low,NULL);

761:   if (size==1) {
762:     VecGetSize(x,&vsize);
763:     VecGetSize(y,&vsize1);
764:     ISCreateStride(PETSC_COMM_SELF,N,0,1,&list1);
765:     VecScatterCreate(x,list1,y,list1,&vecscat);
766:     VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
767:     VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
768:     VecScatterDestroy(&vecscat);
769:     ISDestroy(&list1);
770:   } else {
771:     switch (ndim) {
772:     case 1:
773: #if defined(PETSC_USE_COMPLEX)
774:       fftw_mpi_local_size_1d(dim[0],comm,FFTW_FORWARD,FFTW_ESTIMATE,&local_n0,&local_0_start,&local_n1,&local_1_start);

776:       ISCreateStride(comm,local_n0,local_0_start,1,&list1);
777:       ISCreateStride(comm,local_n0,low,1,&list2);
778:       VecScatterCreate(x,list1,y,list2,&vecscat);
779:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
780:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
781:       VecScatterDestroy(&vecscat);
782:       ISDestroy(&list1);
783:       ISDestroy(&list2);
784: #else
785:       SETERRQ(comm,PETSC_ERR_SUP,"FFTW does not support parallel 1D real transform");
786: #endif
787:       break;
788:     case 2:
789: #if defined(PETSC_USE_COMPLEX)
790:       fftw_mpi_local_size_2d(dim[0],dim[1],comm,&local_n0,&local_0_start);

792:       ISCreateStride(comm,local_n0*dim[1],local_0_start*dim[1],1,&list1);
793:       ISCreateStride(comm,local_n0*dim[1],low,1,&list2);
794:       VecScatterCreate(x,list1,y,list2,&vecscat);
795:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
796:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
797:       VecScatterDestroy(&vecscat);
798:       ISDestroy(&list1);
799:       ISDestroy(&list2);
800: #else
801:       fftw_mpi_local_size_2d_transposed(dim[0],dim[1]/2+1,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);

803:       PetscMalloc1(((PetscInt)local_n0)*dim[1],&indx1);
804:       PetscMalloc1(((PetscInt)local_n0)*dim[1],&indx2);

806:       if (dim[1]%2==0) {
807:         NM = dim[1]+2;
808:       } else {
809:         NM = dim[1]+1;
810:       }
811:       for (i=0; i<local_n0; i++) {
812:         for (j=0; j<dim[1]; j++) {
813:           tempindx  = i*dim[1] + j;
814:           tempindx1 = i*NM + j;

816:           indx1[tempindx]=local_0_start*dim[1]+tempindx;
817:           indx2[tempindx]=low+tempindx1;
818:         }
819:       }

821:       ISCreateGeneral(comm,local_n0*dim[1],indx1,PETSC_COPY_VALUES,&list1);
822:       ISCreateGeneral(comm,local_n0*dim[1],indx2,PETSC_COPY_VALUES,&list2);

824:       VecScatterCreate(x,list1,y,list2,&vecscat);
825:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
826:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
827:       VecScatterDestroy(&vecscat);
828:       ISDestroy(&list1);
829:       ISDestroy(&list2);
830:       PetscFree(indx1);
831:       PetscFree(indx2);
832: #endif
833:       break;

835:     case 3:
836: #if defined(PETSC_USE_COMPLEX)
837:       fftw_mpi_local_size_3d(dim[0],dim[1],dim[2],comm,&local_n0,&local_0_start);

839:       ISCreateStride(comm,local_n0*dim[1]*dim[2],local_0_start*dim[1]*dim[2],1,&list1);
840:       ISCreateStride(comm,local_n0*dim[1]*dim[2],low,1,&list2);
841:       VecScatterCreate(x,list1,y,list2,&vecscat);
842:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
843:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
844:       VecScatterDestroy(&vecscat);
845:       ISDestroy(&list1);
846:       ISDestroy(&list2);
847: #else
848:       /* buggy, needs to be fixed. See src/mat/tests/ex158.c */
849:       SETERRQ(comm,PETSC_ERR_SUP,"FFTW does not support parallel 3D real transform");
850:       fftw_mpi_local_size_3d_transposed(dim[0],dim[1],dim[2]/2+1,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);

852:       PetscMalloc1(((PetscInt)local_n0)*dim[1]*dim[2],&indx1);
853:       PetscMalloc1(((PetscInt)local_n0)*dim[1]*dim[2],&indx2);

855:       if (dim[2]%2==0) NM = dim[2]+2;
856:       else             NM = dim[2]+1;

858:       for (i=0; i<local_n0; i++) {
859:         for (j=0; j<dim[1]; j++) {
860:           for (k=0; k<dim[2]; k++) {
861:             tempindx  = i*dim[1]*dim[2] + j*dim[2] + k;
862:             tempindx1 = i*dim[1]*NM + j*NM + k;

864:             indx1[tempindx]=local_0_start*dim[1]*dim[2]+tempindx;
865:             indx2[tempindx]=low+tempindx1;
866:           }
867:         }
868:       }

870:       ISCreateGeneral(comm,local_n0*dim[1]*dim[2],indx1,PETSC_COPY_VALUES,&list1);
871:       ISCreateGeneral(comm,local_n0*dim[1]*dim[2],indx2,PETSC_COPY_VALUES,&list2);
872:       VecScatterCreate(x,list1,y,list2,&vecscat);
873:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
874:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
875:       VecScatterDestroy(&vecscat);
876:       ISDestroy(&list1);
877:       ISDestroy(&list2);
878:       PetscFree(indx1);
879:       PetscFree(indx2);
880: #endif
881:       break;

883:     default:
884: #if defined(PETSC_USE_COMPLEX)
885:       fftw_mpi_local_size(fftw->ndim_fftw,fftw->dim_fftw,comm,&local_n0,&local_0_start);

887:       ISCreateStride(comm,local_n0*(fftw->partial_dim),local_0_start*(fftw->partial_dim),1,&list1);
888:       ISCreateStride(comm,local_n0*(fftw->partial_dim),low,1,&list2);
889:       VecScatterCreate(x,list1,y,list2,&vecscat);
890:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
891:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
892:       VecScatterDestroy(&vecscat);
893:       ISDestroy(&list1);
894:       ISDestroy(&list2);
895: #else
896:       /* buggy, needs to be fixed. See src/mat/tests/ex158.c */
897:       SETERRQ(comm,PETSC_ERR_SUP,"FFTW does not support parallel DIM>3 real transform");
898:       temp = (fftw->dim_fftw)[fftw->ndim_fftw-1];

900:       (fftw->dim_fftw)[fftw->ndim_fftw-1] = temp/2 + 1;

902:       fftw_mpi_local_size_transposed(fftw->ndim_fftw,fftw->dim_fftw,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);

904:       (fftw->dim_fftw)[fftw->ndim_fftw-1] = temp;

906:       partial_dim = fftw->partial_dim;

908:       PetscMalloc1(((PetscInt)local_n0)*partial_dim,&indx1);
909:       PetscMalloc1(((PetscInt)local_n0)*partial_dim,&indx2);

911:       if (dim[ndim-1]%2==0) NM = 2;
912:       else                  NM = 1;

914:       j = low;
915:       for (i=0,k=1; i<((PetscInt)local_n0)*partial_dim;i++,k++) {
916:         indx1[i] = local_0_start*partial_dim + i;
917:         indx2[i] = j;
918:         if (k%dim[ndim-1]==0) j+=NM;
919:         j++;
920:       }
921:       ISCreateGeneral(comm,local_n0*partial_dim,indx1,PETSC_COPY_VALUES,&list1);
922:       ISCreateGeneral(comm,local_n0*partial_dim,indx2,PETSC_COPY_VALUES,&list2);
923:       VecScatterCreate(x,list1,y,list2,&vecscat);
924:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
925:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
926:       VecScatterDestroy(&vecscat);
927:       ISDestroy(&list1);
928:       ISDestroy(&list2);
929:       PetscFree(indx1);
930:       PetscFree(indx2);
931: #endif
932:       break;
933:     }
934:   }
935:   return(0);
936: }

938: /*@
939:    VecScatterFFTWToPetsc - Converts FFTW output to the PETSc vector.

941:    Collective on Mat

943:     Input Parameters:
944: +   A - FFTW matrix
945: -   x - FFTW vector

947:    Output Parameters:
948: .  y - PETSc vector

950:    Level: intermediate

952:    Note: While doing real transform the FFTW output of backward DFT contains extra zeros at the end of last dimension.
953:          VecScatterFFTWToPetsc removes those extra zeros.

955: .seealso: VecScatterPetscToFFTW()
956: @*/
957: PetscErrorCode VecScatterFFTWToPetsc(Mat A,Vec x,Vec y)
958: {

962:   PetscUseMethod(A,"VecScatterFFTWToPetsc_C",(Mat,Vec,Vec),(A,x,y));
963:   return(0);
964: }

966: PetscErrorCode VecScatterFFTWToPetsc_FFTW(Mat A,Vec x,Vec y)
967: {
969:   MPI_Comm       comm;
970:   Mat_FFT        *fft  = (Mat_FFT*)A->data;
971:   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
972:   PetscInt       N     = fft->N;
973:   PetscInt       ndim  = fft->ndim,*dim=fft->dim;
974:   PetscInt       low;
975:   PetscMPIInt    rank,size;
976:   ptrdiff_t      local_n0,local_0_start;
977:   ptrdiff_t      local_n1,local_1_start;
978:   VecScatter     vecscat;
979:   IS             list1,list2;
980: #if !defined(PETSC_USE_COMPLEX)
981:   PetscInt       i,j,k,partial_dim;
982:   PetscInt       *indx1, *indx2, tempindx, tempindx1;
983:   PetscInt       NM;
984:   ptrdiff_t      temp;
985: #endif

988:   PetscObjectGetComm((PetscObject)A,&comm);
989:   MPI_Comm_size(comm, &size);
990:   MPI_Comm_rank(comm, &rank);
991:   VecGetOwnershipRange(x,&low,NULL);

993:   if (size==1) {
994:     ISCreateStride(comm,N,0,1,&list1);
995:     VecScatterCreate(x,list1,y,list1,&vecscat);
996:     VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
997:     VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
998:     VecScatterDestroy(&vecscat);
999:     ISDestroy(&list1);

1001:   } else {
1002:     switch (ndim) {
1003:     case 1:
1004: #if defined(PETSC_USE_COMPLEX)
1005:       fftw_mpi_local_size_1d(dim[0],comm,FFTW_BACKWARD,FFTW_ESTIMATE,&local_n0,&local_0_start,&local_n1,&local_1_start);

1007:       ISCreateStride(comm,local_n1,local_1_start,1,&list1);
1008:       ISCreateStride(comm,local_n1,low,1,&list2);
1009:       VecScatterCreate(x,list1,y,list2,&vecscat);
1010:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1011:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1012:       VecScatterDestroy(&vecscat);
1013:       ISDestroy(&list1);
1014:       ISDestroy(&list2);
1015: #else
1016:       SETERRQ(comm,PETSC_ERR_SUP,"No support for real parallel 1D FFT");
1017: #endif
1018:       break;
1019:     case 2:
1020: #if defined(PETSC_USE_COMPLEX)
1021:       fftw_mpi_local_size_2d(dim[0],dim[1],comm,&local_n0,&local_0_start);

1023:       ISCreateStride(comm,local_n0*dim[1],local_0_start*dim[1],1,&list1);
1024:       ISCreateStride(comm,local_n0*dim[1],low,1,&list2);
1025:       VecScatterCreate(x,list2,y,list1,&vecscat);
1026:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1027:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1028:       VecScatterDestroy(&vecscat);
1029:       ISDestroy(&list1);
1030:       ISDestroy(&list2);
1031: #else
1032:       fftw_mpi_local_size_2d_transposed(dim[0],dim[1]/2+1,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);

1034:       PetscMalloc1(((PetscInt)local_n0)*dim[1],&indx1);
1035:       PetscMalloc1(((PetscInt)local_n0)*dim[1],&indx2);

1037:       if (dim[1]%2==0) NM = dim[1]+2;
1038:       else             NM = dim[1]+1;

1040:       for (i=0; i<local_n0; i++) {
1041:         for (j=0; j<dim[1]; j++) {
1042:           tempindx = i*dim[1] + j;
1043:           tempindx1 = i*NM + j;

1045:           indx1[tempindx]=local_0_start*dim[1]+tempindx;
1046:           indx2[tempindx]=low+tempindx1;
1047:         }
1048:       }

1050:       ISCreateGeneral(comm,local_n0*dim[1],indx1,PETSC_COPY_VALUES,&list1);
1051:       ISCreateGeneral(comm,local_n0*dim[1],indx2,PETSC_COPY_VALUES,&list2);

1053:       VecScatterCreate(x,list2,y,list1,&vecscat);
1054:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1055:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1056:       VecScatterDestroy(&vecscat);
1057:       ISDestroy(&list1);
1058:       ISDestroy(&list2);
1059:       PetscFree(indx1);
1060:       PetscFree(indx2);
1061: #endif
1062:       break;
1063:     case 3:
1064: #if defined(PETSC_USE_COMPLEX)
1065:       fftw_mpi_local_size_3d(dim[0],dim[1],dim[2],comm,&local_n0,&local_0_start);

1067:       ISCreateStride(comm,local_n0*dim[1]*dim[2],local_0_start*dim[1]*dim[2],1,&list1);
1068:       ISCreateStride(comm,local_n0*dim[1]*dim[2],low,1,&list2);
1069:       VecScatterCreate(x,list1,y,list2,&vecscat);
1070:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1071:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1072:       VecScatterDestroy(&vecscat);
1073:       ISDestroy(&list1);
1074:       ISDestroy(&list2);
1075: #else
1076:       fftw_mpi_local_size_3d_transposed(dim[0],dim[1],dim[2]/2+1,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);

1078:       PetscMalloc1(((PetscInt)local_n0)*dim[1]*dim[2],&indx1);
1079:       PetscMalloc1(((PetscInt)local_n0)*dim[1]*dim[2],&indx2);

1081:       if (dim[2]%2==0) NM = dim[2]+2;
1082:       else             NM = dim[2]+1;

1084:       for (i=0; i<local_n0; i++) {
1085:         for (j=0; j<dim[1]; j++) {
1086:           for (k=0; k<dim[2]; k++) {
1087:             tempindx  = i*dim[1]*dim[2] + j*dim[2] + k;
1088:             tempindx1 = i*dim[1]*NM + j*NM + k;

1090:             indx1[tempindx]=local_0_start*dim[1]*dim[2]+tempindx;
1091:             indx2[tempindx]=low+tempindx1;
1092:           }
1093:         }
1094:       }

1096:       ISCreateGeneral(comm,local_n0*dim[1]*dim[2],indx1,PETSC_COPY_VALUES,&list1);
1097:       ISCreateGeneral(comm,local_n0*dim[1]*dim[2],indx2,PETSC_COPY_VALUES,&list2);

1099:       VecScatterCreate(x,list2,y,list1,&vecscat);
1100:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1101:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1102:       VecScatterDestroy(&vecscat);
1103:       ISDestroy(&list1);
1104:       ISDestroy(&list2);
1105:       PetscFree(indx1);
1106:       PetscFree(indx2);
1107: #endif
1108:       break;
1109:     default:
1110: #if defined(PETSC_USE_COMPLEX)
1111:       fftw_mpi_local_size(fftw->ndim_fftw,fftw->dim_fftw,comm,&local_n0,&local_0_start);

1113:       ISCreateStride(comm,local_n0*(fftw->partial_dim),local_0_start*(fftw->partial_dim),1,&list1);
1114:       ISCreateStride(comm,local_n0*(fftw->partial_dim),low,1,&list2);
1115:       VecScatterCreate(x,list1,y,list2,&vecscat);
1116:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1117:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1118:       VecScatterDestroy(&vecscat);
1119:       ISDestroy(&list1);
1120:       ISDestroy(&list2);
1121: #else
1122:       temp = (fftw->dim_fftw)[fftw->ndim_fftw-1];

1124:       (fftw->dim_fftw)[fftw->ndim_fftw-1] = temp/2 + 1;

1126:       fftw_mpi_local_size_transposed(fftw->ndim_fftw,fftw->dim_fftw,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);

1128:       (fftw->dim_fftw)[fftw->ndim_fftw-1] = temp;

1130:       partial_dim = fftw->partial_dim;

1132:       PetscMalloc1(((PetscInt)local_n0)*partial_dim,&indx1);
1133:       PetscMalloc1(((PetscInt)local_n0)*partial_dim,&indx2);

1135:       if (dim[ndim-1]%2==0) NM = 2;
1136:       else                  NM = 1;

1138:       j = low;
1139:       for (i=0,k=1; i<((PetscInt)local_n0)*partial_dim; i++,k++) {
1140:         indx1[i] = local_0_start*partial_dim + i;
1141:         indx2[i] = j;
1142:         if (k%dim[ndim-1]==0) j+=NM;
1143:         j++;
1144:       }
1145:       ISCreateGeneral(comm,local_n0*partial_dim,indx1,PETSC_COPY_VALUES,&list1);
1146:       ISCreateGeneral(comm,local_n0*partial_dim,indx2,PETSC_COPY_VALUES,&list2);

1148:       VecScatterCreate(x,list2,y,list1,&vecscat);
1149:       VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1150:       VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);
1151:       VecScatterDestroy(&vecscat);
1152:       ISDestroy(&list1);
1153:       ISDestroy(&list2);
1154:       PetscFree(indx1);
1155:       PetscFree(indx2);
1156: #endif
1157:       break;
1158:     }
1159:   }
1160:   return(0);
1161: }

1163: /*
1164:     MatCreate_FFTW - Creates a matrix object that provides FFT via the external package FFTW

1166:   Options Database Keys:
1167: + -mat_fftw_plannerflags - set FFTW planner flags

1169:    Level: intermediate

1171: */
1172: PETSC_EXTERN PetscErrorCode MatCreate_FFTW(Mat A)
1173: {
1175:   MPI_Comm       comm;
1176:   Mat_FFT        *fft=(Mat_FFT*)A->data;
1177:   Mat_FFTW       *fftw;
1178:   PetscInt       n=fft->n,N=fft->N,ndim=fft->ndim,*dim=fft->dim;
1179:   const char     *plans[]={"FFTW_ESTIMATE","FFTW_MEASURE","FFTW_PATIENT","FFTW_EXHAUSTIVE"};
1180:   unsigned       iplans[]={FFTW_ESTIMATE,FFTW_MEASURE,FFTW_PATIENT,FFTW_EXHAUSTIVE};
1181:   PetscBool      flg;
1182:   PetscInt       p_flag,partial_dim=1,ctr;
1183:   PetscMPIInt    size,rank;
1184:   ptrdiff_t      *pdim;
1185:   ptrdiff_t      local_n1,local_1_start;
1186: #if !defined(PETSC_USE_COMPLEX)
1187:   ptrdiff_t      temp;
1188:   PetscInt       N1,tot_dim;
1189: #else
1190:   PetscInt       n1;
1191: #endif

1194:   PetscObjectGetComm((PetscObject)A,&comm);
1195:   MPI_Comm_size(comm, &size);
1196:   MPI_Comm_rank(comm, &rank);

1198:   fftw_mpi_init();
1199:   pdim    = (ptrdiff_t*)calloc(ndim,sizeof(ptrdiff_t));
1200:   pdim[0] = dim[0];
1201: #if !defined(PETSC_USE_COMPLEX)
1202:   tot_dim = 2*dim[0];
1203: #endif
1204:   for (ctr=1; ctr<ndim; ctr++) {
1205:     partial_dim *= dim[ctr];
1206:     pdim[ctr]    = dim[ctr];
1207: #if !defined(PETSC_USE_COMPLEX)
1208:     if (ctr==ndim-1) tot_dim *= (dim[ctr]/2+1);
1209:     else             tot_dim *= dim[ctr];
1210: #endif
1211:   }

1213:   if (size == 1) {
1214: #if defined(PETSC_USE_COMPLEX)
1215:     MatSetSizes(A,N,N,N,N);
1216:     n    = N;
1217: #else
1218:     MatSetSizes(A,tot_dim,tot_dim,tot_dim,tot_dim);
1219:     n    = tot_dim;
1220: #endif

1222:   } else {
1223:     ptrdiff_t local_n0,local_0_start;
1224:     switch (ndim) {
1225:     case 1:
1226: #if !defined(PETSC_USE_COMPLEX)
1227:       SETERRQ(comm,PETSC_ERR_SUP,"FFTW does not support parallel 1D real transform");
1228: #else
1229:       fftw_mpi_local_size_1d(dim[0],comm,FFTW_FORWARD,FFTW_ESTIMATE,&local_n0,&local_0_start,&local_n1,&local_1_start);

1231:       n    = (PetscInt)local_n0;
1232:       n1   = (PetscInt)local_n1;
1233:       MatSetSizes(A,n1,n,N,N);
1234: #endif
1235:       break;
1236:     case 2:
1237: #if defined(PETSC_USE_COMPLEX)
1238:       fftw_mpi_local_size_2d(dim[0],dim[1],comm,&local_n0,&local_0_start);
1239:       /*
1240:        PetscSynchronizedPrintf(comm,"[%d] MatCreateSeqFFTW: local_n0, local_0_start %d %d, N %d,dim %d, %d\n",rank,(PetscInt)local_n0*dim[1],(PetscInt)local_0_start,m,dim[0],dim[1]);
1241:        PetscSynchronizedFlush(comm,PETSC_STDOUT);
1242:        */
1243:       n    = (PetscInt)local_n0*dim[1];
1244:       MatSetSizes(A,n,n,N,N);
1245: #else
1246:       fftw_mpi_local_size_2d_transposed(dim[0],dim[1]/2+1,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);

1248:       n    = 2*(PetscInt)local_n0*(dim[1]/2+1);
1249:       MatSetSizes(A,n,n,2*dim[0]*(dim[1]/2+1),2*dim[0]*(dim[1]/2+1));
1250: #endif
1251:       break;
1252:     case 3:
1253: #if defined(PETSC_USE_COMPLEX)
1254:       fftw_mpi_local_size_3d(dim[0],dim[1],dim[2],comm,&local_n0,&local_0_start);

1256:       n    = (PetscInt)local_n0*dim[1]*dim[2];
1257:       MatSetSizes(A,n,n,N,N);
1258: #else
1259:       fftw_mpi_local_size_3d_transposed(dim[0],dim[1],dim[2]/2+1,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);

1261:       n   = 2*(PetscInt)local_n0*dim[1]*(dim[2]/2+1);
1262:       MatSetSizes(A,n,n,2*dim[0]*dim[1]*(dim[2]/2+1),2*dim[0]*dim[1]*(dim[2]/2+1));
1263: #endif
1264:       break;
1265:     default:
1266: #if defined(PETSC_USE_COMPLEX)
1267:       fftw_mpi_local_size(ndim,pdim,comm,&local_n0,&local_0_start);

1269:       n    = (PetscInt)local_n0*partial_dim;
1270:       MatSetSizes(A,n,n,N,N);
1271: #else
1272:       temp = pdim[ndim-1];

1274:       pdim[ndim-1] = temp/2 + 1;

1276:       fftw_mpi_local_size_transposed(ndim,pdim,comm,&local_n0,&local_0_start,&local_n1,&local_1_start);

1278:       n  = 2*(PetscInt)local_n0*partial_dim*pdim[ndim-1]/temp;
1279:       N1 = 2*N*(PetscInt)pdim[ndim-1]/((PetscInt) temp);

1281:       pdim[ndim-1] = temp;

1283:       MatSetSizes(A,n,n,N1,N1);
1284: #endif
1285:       break;
1286:     }
1287:   }
1288:   free(pdim);
1289:   PetscObjectChangeTypeName((PetscObject)A,MATFFTW);
1290:   PetscNewLog(A,&fftw);
1291:   fft->data = (void*)fftw;

1293:   fft->n            = n;
1294:   fftw->ndim_fftw   = (ptrdiff_t)ndim; /* This is dimension of fft */
1295:   fftw->partial_dim = partial_dim;

1297:   PetscMalloc1(ndim, &(fftw->dim_fftw));
1298:   if (size == 1) {
1299: #if defined(PETSC_USE_64BIT_INDICES)
1300:     fftw->iodims = (fftw_iodim64 *) malloc(sizeof(fftw_iodim64) * ndim);
1301: #else
1302:     fftw->iodims = (fftw_iodim *) malloc(sizeof(fftw_iodim) * ndim);
1303: #endif
1304:   }

1306:   for (ctr=0;ctr<ndim;ctr++) (fftw->dim_fftw)[ctr]=dim[ctr];

1308:   fftw->p_forward  = NULL;
1309:   fftw->p_backward = NULL;
1310:   fftw->p_flag     = FFTW_ESTIMATE;

1312:   if (size == 1) {
1313:     A->ops->mult          = MatMult_SeqFFTW;
1314:     A->ops->multtranspose = MatMultTranspose_SeqFFTW;
1315:   } else {
1316:     A->ops->mult          = MatMult_MPIFFTW;
1317:     A->ops->multtranspose = MatMultTranspose_MPIFFTW;
1318:   }
1319:   fft->matdestroy = MatDestroy_FFTW;
1320:   A->assembled    = PETSC_TRUE;
1321:   A->preallocated = PETSC_TRUE;

1323:   PetscObjectComposeFunction((PetscObject)A,"MatCreateVecsFFTW_C",MatCreateVecsFFTW_FFTW);
1324:   PetscObjectComposeFunction((PetscObject)A,"VecScatterPetscToFFTW_C",VecScatterPetscToFFTW_FFTW);
1325:   PetscObjectComposeFunction((PetscObject)A,"VecScatterFFTWToPetsc_C",VecScatterFFTWToPetsc_FFTW);

1327:   /* get runtime options */
1328:   PetscOptionsBegin(PetscObjectComm((PetscObject)A),((PetscObject)A)->prefix,"FFTW Options","Mat");
1329:   PetscOptionsEList("-mat_fftw_plannerflags","Planner Flags","None",plans,4,plans[0],&p_flag,&flg);
1330:   if (flg) {
1331:     fftw->p_flag = iplans[p_flag];
1332:   }
1333:   PetscOptionsEnd();
1334:   return(0);
1335: }