xref: /petsc/src/mat/impls/fft/fftw/fftw.c (revision 54efbe565ec03335f43e1133a2e5a0491439bfe6)
1 
2 /*
3     Provides an interface to the FFTW package.
4     Testing examples can be found in ~src/mat/examples/tests
5 */
6 
7 #include <../src/mat/impls/fft/fft.h>   /*I "petscmat.h" I*/
8 EXTERN_C_BEGIN
9 #include <fftw3-mpi.h>
10 EXTERN_C_END
11 
12 typedef struct {
13   ptrdiff_t   ndim_fftw,*dim_fftw;
14   fftw_plan   p_forward,p_backward;
15   unsigned    p_flag; /* planner flags, FFTW_ESTIMATE,FFTW_MEASURE, FFTW_PATIENT, FFTW_EXHAUSTIVE */
16   PetscScalar *finarray,*foutarray,*binarray,*boutarray; /* keep track of arrays becaue fftw plan should be
17                                                             executed for the arrays with which the plan was created */
18 } Mat_FFTW;
19 
20 extern PetscErrorCode MatMult_SeqFFTW(Mat,Vec,Vec);
21 extern PetscErrorCode MatMultTranspose_SeqFFTW(Mat,Vec,Vec);
22 extern PetscErrorCode MatMult_MPIFFTW(Mat,Vec,Vec);
23 extern PetscErrorCode MatMultTranspose_MPIFFTW(Mat,Vec,Vec);
24 extern PetscErrorCode MatDestroy_FFTW(Mat);
25 extern PetscErrorCode VecDestroy_MPIFFTW(Vec);
26 extern PetscErrorCode MatGetVecs_FFTW(Mat,Vec*,Vec*);
27 
28 #undef __FUNCT__
29 #define __FUNCT__ "MatMult_SeqFFTW"
30 PetscErrorCode MatMult_SeqFFTW(Mat A,Vec x,Vec y)
31 {
32   PetscErrorCode ierr;
33   Mat_FFT        *fft  = (Mat_FFT*)A->data;
34   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
35   PetscScalar    *x_array,*y_array;
36   PetscInt       ndim=fft->ndim,*dim=fft->dim;
37 
38   PetscFunctionBegin;
39 #if !defined(PETSC_USE_COMPLEX)
40 
41   SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"not support for real numbers");
42 #endif
43   ierr = VecGetArray(x,&x_array);CHKERRQ(ierr);
44   ierr = VecGetArray(y,&y_array);CHKERRQ(ierr);
45   if (!fftw->p_forward){ /* create a plan, then excute it */
46     switch (ndim){
47     case 1:
48       fftw->p_forward = fftw_plan_dft_1d(dim[0],(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_FORWARD,fftw->p_flag);
49       break;
50     case 2:
51       fftw->p_forward = fftw_plan_dft_2d(dim[0],dim[1],(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_FORWARD,fftw->p_flag);
52       break;
53     case 3:
54       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);
55       break;
56     default:
57       fftw->p_forward = fftw_plan_dft(ndim,dim,(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_FORWARD,fftw->p_flag);
58       break;
59     }
60     fftw->finarray  = x_array;
61     fftw->foutarray = y_array;
62     /* Warning: if (fftw->p_flag!==FFTW_ESTIMATE) The data in the in/out arrays is overwritten!
63                 planning should be done before x is initialized! See FFTW manual sec2.1 or sec4 */
64     fftw_execute(fftw->p_forward);
65   } else { /* use existing plan */
66     if (fftw->finarray != x_array || fftw->foutarray != y_array){ /* use existing plan on new arrays */
67       fftw_execute_dft(fftw->p_forward,(fftw_complex*)x_array,(fftw_complex*)y_array);
68     } else {
69       fftw_execute(fftw->p_forward);
70     }
71   }
72   ierr = VecRestoreArray(y,&y_array);CHKERRQ(ierr);
73   ierr = VecRestoreArray(x,&x_array);CHKERRQ(ierr);
74   PetscFunctionReturn(0);
75 }
76 
77 #undef __FUNCT__
78 #define __FUNCT__ "MatMultTranspose_SeqFFTW"
79 PetscErrorCode MatMultTranspose_SeqFFTW(Mat A,Vec x,Vec y)
80 {
81   PetscErrorCode ierr;
82   Mat_FFT        *fft = (Mat_FFT*)A->data;
83   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
84   PetscScalar    *x_array,*y_array;
85   PetscInt       ndim=fft->ndim,*dim=fft->dim;
86 
87   PetscFunctionBegin;
88 #if !defined(PETSC_USE_COMPLEX)
89   SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"not support for real numbers");
90 #endif
91   ierr = VecGetArray(x,&x_array);CHKERRQ(ierr);
92   ierr = VecGetArray(y,&y_array);CHKERRQ(ierr);
93   if (!fftw->p_backward){ /* create a plan, then excute it */
94     switch (ndim){
95     case 1:
96       fftw->p_backward = fftw_plan_dft_1d(dim[0],(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_BACKWARD,fftw->p_flag);
97       break;
98     case 2:
99       fftw->p_backward = fftw_plan_dft_2d(dim[0],dim[1],(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_BACKWARD,fftw->p_flag);
100       break;
101     case 3:
102       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);
103       break;
104     default:
105       fftw->p_backward = fftw_plan_dft(ndim,dim,(fftw_complex*)x_array,(fftw_complex*)y_array,FFTW_BACKWARD,fftw->p_flag);
106       break;
107     }
108     fftw->binarray  = x_array;
109     fftw->boutarray = y_array;
110     fftw_execute(fftw->p_backward);CHKERRQ(ierr);
111   } else { /* use existing plan */
112     if (fftw->binarray != x_array || fftw->boutarray != y_array){ /* use existing plan on new arrays */
113       fftw_execute_dft(fftw->p_backward,(fftw_complex*)x_array,(fftw_complex*)y_array);
114     } else {
115       fftw_execute(fftw->p_backward);CHKERRQ(ierr);
116     }
117   }
118   ierr = VecRestoreArray(y,&y_array);CHKERRQ(ierr);
119   ierr = VecRestoreArray(x,&x_array);CHKERRQ(ierr);
120   PetscFunctionReturn(0);
121 }
122 
123 #undef __FUNCT__
124 #define __FUNCT__ "MatMult_MPIFFTW"
125 PetscErrorCode MatMult_MPIFFTW(Mat A,Vec x,Vec y)
126 {
127   PetscErrorCode ierr;
128   Mat_FFT        *fft  = (Mat_FFT*)A->data;
129   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
130   PetscScalar    *x_array,*y_array;
131   PetscInt       ndim=fft->ndim,*dim=fft->dim;
132   MPI_Comm       comm=((PetscObject)A)->comm;
133 // PetscInt ctr;
134 //  ptrdiff_t      ndim1=(ptrdiff_t) ndim,*pdim;
135 //  ndim1=(ptrdiff_t) ndim;
136 //  pdim = (ptrdiff_t *)calloc(ndim,sizeof(ptrdiff_t));
137 
138 //  for(ctr=0;ctr<ndim;ctr++)
139 //     {
140 //      pdim[ctr] = dim[ctr];
141 //     }
142 
143   PetscFunctionBegin;
144 //#if !defined(PETSC_USE_COMPLEX)
145 //  SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"not support for real numbers");
146 //#endif
147 //  pdim = (ptrdiff_t *)calloc(ndim,sizeof(ptrdiff_t));
148 //  for (ctr=0; ctr<ndim; ctr++) pdim[ctr] = dim[ctr];
149 
150   ierr = VecGetArray(x,&x_array);CHKERRQ(ierr);
151   ierr = VecGetArray(y,&y_array);CHKERRQ(ierr);
152   if (!fftw->p_forward){ /* create a plan, then excute it */
153     switch (ndim){
154     case 1:
155 #if defined(PETSC_USE_COMPLEX)
156       fftw->p_forward = fftw_mpi_plan_dft_1d(dim[0],(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_FORWARD,fftw->p_flag);
157 #endif
158       break;
159     case 2:
160 #if defined(PETSC_USE_COMPLEX)
161       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);
162 #else
163       printf("The code comes here \n");
164       fftw->p_forward = fftw_mpi_plan_dft_r2c_2d(dim[0],dim[1],(double *)x_array,(fftw_complex*)y_array,comm,FFTW_ESTIMATE);
165 #endif
166       break;
167     case 3:
168 #if defined(PETSC_USE_COMPLEX)
169       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);
170 #else
171       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);
172 #endif
173       break;
174     default:
175 #if defined(PETSC_USE_COMPLEX)
176       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);
177 #else
178       fftw->p_forward = fftw_mpi_plan_dft_r2c(fftw->ndim_fftw,fftw->dim_fftw,(double *)x_array,(fftw_complex*)y_array,comm,FFTW_ESTIMATE);
179 #endif
180  //     fftw->p_forward = fftw_mpi_plan_dft(ndim,dim,(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_FORWARD,fftw->p_flag);
181       break;
182     }
183     fftw->finarray  = x_array;
184     fftw->foutarray = y_array;
185     /* Warning: if (fftw->p_flag!==FFTW_ESTIMATE) The data in the in/out arrays is overwritten!
186                 planning should be done before x is initialized! See FFTW manual sec2.1 or sec4 */
187     fftw_execute(fftw->p_forward);
188   } else { /* use existing plan */
189     if (fftw->finarray != x_array || fftw->foutarray != y_array){ /* use existing plan on new arrays */
190       fftw_execute_dft(fftw->p_forward,(fftw_complex*)x_array,(fftw_complex*)y_array);
191     } else {
192       fftw_execute(fftw->p_forward);
193     }
194   }
195   ierr = VecRestoreArray(y,&y_array);CHKERRQ(ierr);
196   ierr = VecRestoreArray(x,&x_array);CHKERRQ(ierr);
197   PetscFunctionReturn(0);
198 }
199 
200 #undef __FUNCT__
201 #define __FUNCT__ "MatMultTranspose_MPIFFTW"
202 PetscErrorCode MatMultTranspose_MPIFFTW(Mat A,Vec x,Vec y)
203 {
204   PetscErrorCode ierr;
205   Mat_FFT        *fft  = (Mat_FFT*)A->data;
206   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
207   PetscScalar    *x_array,*y_array;
208   PetscInt       ndim=fft->ndim,*dim=fft->dim;
209   MPI_Comm       comm=((PetscObject)A)->comm;
210 //  PetscInt       ctr;
211 //  ptrdiff_t      ndim1=(ptrdiff_t)ndim,*pdim;
212 //  ndim1=(ptrdiff_t) ndim;
213 //  pdim = (ptrdiff_t *)calloc(ndim,sizeof(ptrdiff_t));
214 
215 //  for(ctr=0;ctr<ndim;ctr++)
216 //     {
217 //      pdim[ctr] = dim[ctr];
218 //     }
219 
220   PetscFunctionBegin;
221 //#if !defined(PETSC_USE_COMPLEX)
222 //  SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"not support for real numbers");
223 //#endif
224 //  ierr = PetscMalloc(ndim*sizeof(ptrdiff_t), (ptrdiff_t *)&pdim);CHKERRQ(ierr);
225 // should pdim be a member of Mat_FFTW?
226 //  for (ctr=0; ctr<ndim; ctr++) pdim[ctr] = dim[ctr];
227 
228   ierr = VecGetArray(x,&x_array);CHKERRQ(ierr);
229   ierr = VecGetArray(y,&y_array);CHKERRQ(ierr);
230   if (!fftw->p_backward){ /* create a plan, then excute it */
231     switch (ndim){
232     case 1:
233 #if defined(PETSC_USE_COMPLEX)
234       fftw->p_backward = fftw_mpi_plan_dft_1d(dim[0],(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_BACKWARD,fftw->p_flag);
235 #endif
236       break;
237     case 2:
238 #if defined(PETSC_USE_COMPLEX)
239       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);
240 #else
241       fftw->p_backward = fftw_mpi_plan_dft_c2r_2d(dim[0],dim[1],(fftw_complex*)x_array,(double *)y_array,comm,FFTW_ESTIMATE);
242 #endif
243       break;
244     case 3:
245 #if defined(PETSC_USE_COMPLEX)
246       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);
247 #else
248       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);
249 #endif
250       break;
251     default:
252 #if defined(PETSC_USE_COMPLEX)
253       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);
254 #else
255       fftw->p_backward = fftw_mpi_plan_dft_c2r(fftw->ndim_fftw,fftw->dim_fftw,(fftw_complex*)x_array,(double *)y_array,comm,FFTW_ESTIMATE);
256 #endif
257 //      fftw->p_backward = fftw_mpi_plan_dft(ndim,dim,(fftw_complex*)x_array,(fftw_complex*)y_array,comm,FFTW_BACKWARD,fftw->p_flag);
258       break;
259     }
260     fftw->binarray  = x_array;
261     fftw->boutarray = y_array;
262     fftw_execute(fftw->p_backward);CHKERRQ(ierr);
263   } else { /* use existing plan */
264     if (fftw->binarray != x_array || fftw->boutarray != y_array){ /* use existing plan on new arrays */
265       fftw_execute_dft(fftw->p_backward,(fftw_complex*)x_array,(fftw_complex*)y_array);
266     } else {
267       fftw_execute(fftw->p_backward);CHKERRQ(ierr);
268     }
269   }
270   ierr = VecRestoreArray(y,&y_array);CHKERRQ(ierr);
271   ierr = VecRestoreArray(x,&x_array);CHKERRQ(ierr);
272   PetscFunctionReturn(0);
273 }
274 
275 #undef __FUNCT__
276 #define __FUNCT__ "MatDestroy_FFTW"
277 PetscErrorCode MatDestroy_FFTW(Mat A)
278 {
279   Mat_FFT        *fft = (Mat_FFT*)A->data;
280   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
281   PetscErrorCode ierr;
282 
283   PetscFunctionBegin;
284 #if !defined(PETSC_USE_COMPLEX)
285   SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"not support for real numbers");
286 #endif
287   fftw_destroy_plan(fftw->p_forward);
288   fftw_destroy_plan(fftw->p_backward);
289   ierr = PetscFree(fftw->dim_fftw);CHKERRQ(ierr);
290   ierr = PetscFree(fft->data);CHKERRQ(ierr);
291   PetscFunctionReturn(0);
292 }
293 
294 #include <../src/vec/vec/impls/mpi/pvecimpl.h>   /*I  "petscvec.h"   I*/
295 #undef __FUNCT__
296 #define __FUNCT__ "VecDestroy_MPIFFTW"
297 PetscErrorCode VecDestroy_MPIFFTW(Vec v)
298 {
299   PetscErrorCode  ierr;
300   PetscScalar     *array;
301 
302   PetscFunctionBegin;
303 #if !defined(PETSC_USE_COMPLEX)
304   SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"not support for real numbers");
305 #endif
306   ierr = VecGetArray(v,&array);CHKERRQ(ierr);
307   fftw_free((fftw_complex*)array);CHKERRQ(ierr);
308   ierr = VecRestoreArray(v,&array);CHKERRQ(ierr);
309   ierr = VecDestroy_MPI(v);CHKERRQ(ierr);
310   PetscFunctionReturn(0);
311 }
312 
313 #undef __FUNCT__
314 #define __FUNCT__ "MatGetVecs1DC_FFTW"
315 /*
316    MatGetVecs_FFTW1D - Get Vectors(s) compatible with matrix, i.e. with the
317      parallel layout determined by FFTW-1D
318 
319 */
320 PetscErrorCode  MatGetVecs_FFTW1D(Mat A,Vec *fin,Vec *fout,Vec *bin,Vec *bout)
321 {
322   PetscErrorCode ierr;
323   PetscMPIInt    size,rank;
324   MPI_Comm       comm=((PetscObject)A)->comm;
325   Mat_FFT        *fft = (Mat_FFT*)A->data;
326 //  Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
327   PetscInt       N=fft->N;
328   PetscInt       ndim=fft->ndim,*dim=fft->dim;
329   ptrdiff_t      f_alloc_local,f_local_n0,f_local_0_start;
330   ptrdiff_t      f_local_n1,f_local_1_end;
331   ptrdiff_t      b_alloc_local,b_local_n0,b_local_0_start;
332   ptrdiff_t      b_local_n1,b_local_1_end;
333   fftw_complex   *data_fin,*data_fout,*data_bin,*data_bout;
334 
335   PetscFunctionBegin;
336 #if !defined(PETSC_USE_COMPLEX)
337   SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"not support for real numbers");
338 #endif
339   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
340   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
341   if (size == 1){
342     SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"Works only for parallel 1D");
343   }
344   else {
345       if (ndim>1){
346         SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"Works only for parallel 1D");}
347       else {
348           f_alloc_local = fftw_mpi_local_size_1d(dim[0],comm,FFTW_FORWARD,FFTW_ESTIMATE,&f_local_n0,&f_local_0_start,&f_local_n1,&f_local_1_end);
349           b_alloc_local = fftw_mpi_local_size_1d(dim[0],comm,FFTW_BACKWARD,FFTW_ESTIMATE,&b_local_n0,&b_local_0_start,&b_local_n1,&b_local_1_end);
350           if (fin) {
351             data_fin  = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*f_alloc_local);
352             ierr = VecCreateMPIWithArray(comm,f_local_n0,N,(const PetscScalar*)data_fin,fin);CHKERRQ(ierr);
353             (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
354           }
355           if (fout) {
356             data_fout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*f_alloc_local);
357             ierr = VecCreateMPIWithArray(comm,f_local_n1,N,(const PetscScalar*)data_fout,fout);CHKERRQ(ierr);
358             (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
359           }
360           if (bin) {
361             data_bin  = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*b_alloc_local);
362             ierr = VecCreateMPIWithArray(comm,b_local_n0,N,(const PetscScalar*)data_bin,bin);CHKERRQ(ierr);
363             (*bin)->ops->destroy   = VecDestroy_MPIFFTW;
364           }
365           if (bout) {
366             data_bout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*b_alloc_local);
367             ierr = VecCreateMPIWithArray(comm,b_local_n1,N,(const PetscScalar*)data_bout,bout);CHKERRQ(ierr);
368             (*bout)->ops->destroy   = VecDestroy_MPIFFTW;
369           }
370   }
371   if (fin){
372     ierr = PetscLayoutReference(A->cmap,&(*fin)->map);CHKERRQ(ierr);
373   }
374   if (fout){
375     ierr = PetscLayoutReference(A->rmap,&(*fout)->map);CHKERRQ(ierr);
376   }
377   if (bin){
378     ierr = PetscLayoutReference(A->rmap,&(*bin)->map);CHKERRQ(ierr);
379   }
380   if (bout){
381     ierr = PetscLayoutReference(A->rmap,&(*bout)->map);CHKERRQ(ierr);
382   }
383   PetscFunctionReturn(0);
384 }
385 
386 
387 }
388 
389 #undef __FUNCT__
390 #define __FUNCT__ "MatGetVecs_FFTW"
391 /*
392    MatGetVecs_FFTW - Get vector(s) compatible with the matrix, i.e. with the
393      parallel layout determined by FFTW
394 
395    Collective on Mat
396 
397    Input Parameter:
398 .  mat - the matrix
399 
400    Output Parameter:
401 +   fin - (optional) input vector of forward FFTW
402 -   fout - (optional) output vector of forward FFTW
403 
404   Level: advanced
405 
406 .seealso: MatCreateFFTW()
407 */
408 PetscErrorCode  MatGetVecs_FFTW(Mat A,Vec *fin,Vec *fout)
409 {
410   PetscErrorCode ierr;
411   PetscMPIInt    size,rank;
412   MPI_Comm       comm=((PetscObject)A)->comm;
413   Mat_FFT        *fft = (Mat_FFT*)A->data;
414   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
415   PetscInt       N=fft->N, N1, n1,vsize;
416 
417   PetscFunctionBegin;
418 //#if !defined(PETSC_USE_COMPLEX)
419 //  SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"not support for real numbers");
420 //#endif
421   PetscValidHeaderSpecific(A,MAT_CLASSID,1);
422   PetscValidType(A,1);
423 
424   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
425   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
426   if (size == 1){ /* sequential case */
427     if (fin) {ierr = VecCreateSeq(PETSC_COMM_SELF,N,fin);CHKERRQ(ierr);}
428     if (fout){ierr = VecCreateSeq(PETSC_COMM_SELF,N,fout);CHKERRQ(ierr);}
429     printf("The code successfully comes at the end of the routine with one processor\n");
430   } else {        /* mpi case */
431     ptrdiff_t      alloc_local,local_n0,local_0_start;
432     ptrdiff_t      local_n1,local_1_end;
433     PetscInt       ndim=fft->ndim,*dim=fft->dim,n=fft->n;
434     fftw_complex   *data_fin,*data_fout;
435     double         *data_finr ;
436     ptrdiff_t local_1_start;
437 //    PetscInt ctr;
438 //    ptrdiff_t      ndim1,*pdim;
439 //    ndim1=(ptrdiff_t) ndim;
440 //    pdim = (ptrdiff_t *)calloc(ndim,sizeof(ptrdiff_t));
441 
442 //    for(ctr=0;ctr<ndim;ctr++)
443 //        {k
444 //           pdim[ctr] = dim[ctr];
445 //       }
446 
447 
448 
449     switch (ndim){
450     case 1:
451       /* Get local size */
452       /* We need to write an error message here saying that one cannot call this routine when doing paralllel 1D complex FFTW */
453 //      SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"Works only for parallel Multi-dimensional FFTW, Dimension>1. Check Documentation for MatGetVecs_FFTW1D routine");
454       alloc_local = fftw_mpi_local_size_1d(dim[0],comm,FFTW_FORWARD,FFTW_ESTIMATE,&local_n0,&local_0_start,&local_n1,&local_1_end);
455       if (fin) {
456         data_fin  = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
457         ierr = VecCreateMPIWithArray(comm,local_n0,N,(const PetscScalar*)data_fin,fin);CHKERRQ(ierr);
458         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
459       }
460       if (fout) {
461         data_fout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
462         ierr = VecCreateMPIWithArray(comm,local_n1,N,(const PetscScalar*)data_fout,fout);CHKERRQ(ierr);
463         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
464       }
465       break;
466     case 2:
467 #if !defined(PETSC_USE_COMPLEX)
468       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);
469       N1 = 2*dim[0]*(dim[1]/2+1); n1 = 2*local_n0*(dim[1]/2+1);
470       if (fin) {
471         data_finr=(double *)fftw_malloc(sizeof(double)*alloc_local*2);
472         ierr = VecCreateMPIWithArray(PETSC_COMM_WORLD,(PetscInt)n1,N1,(PetscScalar*)data_finr,fin);CHKERRQ(ierr);
473         ierr = VecGetSize(*fin,&vsize);CHKERRQ(ierr);
474         //printf("The code comes here with vector size %d\n",vsize);
475         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
476       }
477       if (fout) {
478         data_fout=(fftw_complex *)fftw_malloc(sizeof(fftw_complex)*alloc_local);
479         ierr = VecCreateMPIWithArray(PETSC_COMM_WORLD,n1,N1,(PetscScalar*)data_fout,fout);CHKERRQ(ierr);
480         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
481       }
482       printf("Vector size from fftw.c is  given by %d, %d\n",n1,N1);
483 
484 #else
485       /* Get local size */
486      printf("Hope this does not come here");
487       alloc_local = fftw_mpi_local_size_2d(dim[0],dim[1],comm,&local_n0,&local_0_start);
488       if (fin) {
489         data_fin  = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
490         ierr = VecCreateMPIWithArray(comm,n,N,(const PetscScalar*)data_fin,fin);CHKERRQ(ierr);
491         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
492       }
493       if (fout) {
494         data_fout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
495         ierr = VecCreateMPIWithArray(comm,n,N,(const PetscScalar*)data_fout,fout);CHKERRQ(ierr);
496         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
497       }
498      printf("Hope this does not come here");
499 #endif
500       break;
501     case 3:
502       /* Get local size */
503 #if !defined(PETSC_USE_COMPLEX)
504       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);
505       N1 = 2*dim[0]*dim[1]*(dim[2]/2+1); n1 = 2*local_n0*dim[1]*(dim[2]/2+1);
506       if (fin) {
507         data_finr=(double *)fftw_malloc(sizeof(double)*alloc_local*2);
508         ierr = VecCreateMPIWithArray(PETSC_COMM_WORLD,(PetscInt)n1,N1,(PetscScalar*)data_finr,fin);CHKERRQ(ierr);
509         ierr = VecGetSize(*fin,&vsize);CHKERRQ(ierr);
510         //printf("The code comes here with vector size %d\n",vsize);
511         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
512       }
513       if (fout) {
514         data_fout=(fftw_complex *)fftw_malloc(sizeof(fftw_complex)*alloc_local);
515         ierr = VecCreateMPIWithArray(PETSC_COMM_WORLD,n1,N1,(PetscScalar*)data_fout,fout);CHKERRQ(ierr);
516         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
517       }
518       printf("Vector size from fftw.c is  given by %d, %d\n",n1,N1);
519 
520 
521 #else
522       alloc_local = fftw_mpi_local_size_3d(dim[0],dim[1],dim[2],comm,&local_n0,&local_0_start);
523 //      printf("The quantity n is %d",n);
524       if (fin) {
525         data_fin  = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
526         ierr = VecCreateMPIWithArray(comm,n,N,(const PetscScalar*)data_fin,fin);CHKERRQ(ierr);
527         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
528       }
529       if (fout) {
530         data_fout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
531         ierr = VecCreateMPIWithArray(comm,n,N,(const PetscScalar*)data_fout,fout);CHKERRQ(ierr);
532         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
533       }
534 #endif
535       break;
536     default:
537       /* Get local size */
538 #if !defined(PETSC_USE_COMPLEX)
539   SETERRQ(comm,PETSC_ERR_SUP,"Not done yet");
540 #else
541       alloc_local = fftw_mpi_local_size(fftw->ndim_fftw,fftw->dim_fftw,comm,&local_n0,&local_0_start);
542 //      printf("The value of alloc local is %d from process %d\n",alloc_local,rank);
543 //      printf("The value of alloc local is %d",alloc_local);
544 //      pdim=(ptrdiff_t *)calloc(ndim,sizeof(ptrdiff_t));
545 //      for(i=0;i<ndim;i++)
546 //         {
547 //          pdim[i]=dim[i];printf("%d",pdim[i]);
548 //         }
549 //      alloc_local = fftw_mpi_local_size(ndim,pdim,comm,&local_n0,&local_0_start);
550 //      printf("The quantity n is %d",n);
551       if (fin) {
552         data_fin  = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
553         ierr = VecCreateMPIWithArray(comm,n,N,(const PetscScalar*)data_fin,fin);CHKERRQ(ierr);
554         (*fin)->ops->destroy   = VecDestroy_MPIFFTW;
555       }
556       if (fout) {
557         data_fout = (fftw_complex*)fftw_malloc(sizeof(fftw_complex)*alloc_local);
558         ierr = VecCreateMPIWithArray(comm,n,N,(const PetscScalar*)data_fout,fout);CHKERRQ(ierr);
559         (*fout)->ops->destroy   = VecDestroy_MPIFFTW;
560       }
561 #endif
562       break;
563     }
564   }
565 //  if (fin){
566 //    ierr = PetscLayoutReference(A->cmap,&(*fin)->map);CHKERRQ(ierr);
567 //  }
568 //  if (fout){
569 //    ierr = PetscLayoutReference(A->rmap,&(*fout)->map);CHKERRQ(ierr);
570 //  }
571   PetscFunctionReturn(0);
572 }
573 
574 #undef __FUNCT__
575 #define __FUNCT__ "InputTransformFFT"
576 PetscErrorCode InputTransformFFT(Mat A,Vec x,Vec y)
577 {
578   PetscErrorCode ierr;
579   PetscFunctionBegin;
580   ierr = PetscTryMethod(A,"InputTransformFFT_C",(Mat,Vec,Vec),(A,x,y));CHKERRQ(ierr);
581   PetscFunctionReturn(0);
582 }
583 
584 /*
585       InputTransformFFT_FFTW - Copies the user data to the vector that goes into FFTW block
586   Input A, x, y
587   A - FFTW matrix
588   x - user data
589   Options Database Keys:
590 + -mat_fftw_plannerflags - set FFTW planner flags
591 
592    Level: intermediate
593 
594 */
595 
596 EXTERN_C_BEGIN
597 #undef __FUNCT__
598 #define __FUNCT__ "InputTransformFFT_FTTW"
599 PetscErrorCode InputTransformFFT_FFTW(Mat A,Vec x,Vec y)
600 {
601   PetscErrorCode ierr;
602   MPI_Comm       comm=((PetscObject)A)->comm;
603   Mat_FFT        *fft = (Mat_FFT*)A->data;
604   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
605   PetscInt       N=fft->N, N1, n1 ,NM;
606   PetscInt       ndim=fft->ndim,*dim=fft->dim,n=fft->n;
607   PetscInt       low, *indx1, *indx2, tempindx, tempindx1, *indx3, *indx4;
608   PetscInt       i,j,k,rank,size;
609   ptrdiff_t      alloc_local,local_n0,local_0_start;
610   ptrdiff_t      local_n1,local_1_start;
611   VecScatter     vecscat;
612   IS             list1,list2;
613 
614   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
615   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
616   ierr = VecGetOwnershipRange(y,&low,PETSC_NULL);
617   printf("Local ownership starts at %d\n",low);
618 
619  switch (ndim){
620  case 1:
621   SETERRQ(comm,PETSC_ERR_SUP,"Not Supported by FFTW");
622   break;
623  case 2:
624       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);
625       N1 = 2*dim[0]*(dim[1]/2+1); n1 = 2*local_n0*(dim[1]/2+1);
626 
627       ierr = PetscMalloc(sizeof(PetscInt)*((PetscInt)local_n0)*N1,&indx1);CHKERRQ(ierr);
628       ierr = PetscMalloc(sizeof(PetscInt)*((PetscInt)local_n0)*N1,&indx2);CHKERRQ(ierr);
629       printf("Val local_0_start = %ld\n",local_0_start);
630 
631       if (dim[1]%2==0)
632         NM = dim[1]+2;
633       else
634         NM = dim[1]+1;
635 
636       for (i=0;i<local_n0;i++){
637          for (j=0;j<dim[1];j++){
638             tempindx = i*dim[1] + j;
639             tempindx1 = i*NM + j;
640             indx1[tempindx]=local_0_start*dim[1]+tempindx;
641             indx2[tempindx]=low+tempindx1;
642            // printf("Val tempindx1 = %d\n",tempindx1);
643   //          printf("index1 %d from proc %d is \n",indx1[tempindx],rank);
644   //          printf("index2 %d from proc %d is \n",indx2[tempindx],rank);
645   //          printf("-------------------------\n",indx2[tempindx],rank);
646         }
647      }
648 
649       ierr = ISCreateGeneral(comm,local_n0*dim[1],indx1,PETSC_COPY_VALUES,&list1);CHKERRQ(ierr);
650       ierr = ISCreateGeneral(comm,local_n0*dim[1],indx2,PETSC_COPY_VALUES,&list2);CHKERRQ(ierr);
651 
652       ierr = VecScatterCreate(x,list1,y,list2,&vecscat);CHKERRQ(ierr);
653       ierr = VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
654       ierr = VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
655       ierr = VecScatterDestroy(&vecscat);CHKERRQ(ierr);
656       break;
657 
658  case 3:
659       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);
660       N1 = 2*dim[0]*dim[1]*(dim[2]/2+1); n1 = 2*local_n0*dim[1]*(dim[2]/2+1);
661 
662       ierr = PetscMalloc(sizeof(PetscInt)*((PetscInt)local_n0)*N1,&indx1);CHKERRQ(ierr);
663       ierr = PetscMalloc(sizeof(PetscInt)*((PetscInt)local_n0)*N1,&indx2);CHKERRQ(ierr);
664       printf("Val local_0_start = %ld\n",local_0_start);
665 
666       if (dim[2]%2==0)
667         NM = dim[2]+2;
668       else
669         NM = dim[2]+1;
670 
671       for (i=0;i<local_n0;i++){
672          for (j=0;j<dim[1];j++){
673             for (k=0;k<dim[2];k++){
674                tempindx = i*dim[1]*dim[2] + j*dim[2] + k;
675                tempindx1 = i*dim[1]*NM + j*NM + k;
676                indx1[tempindx]=local_0_start*dim[1]*dim[2]+tempindx;
677                indx2[tempindx]=low+tempindx1;
678             }
679            // printf("Val tempindx1 = %d\n",tempindx1);
680            // printf("index1 %d from proc %d is \n",indx1[tempindx],rank);
681            // printf("index2 %d from proc %d is \n",indx2[tempindx],rank);
682            // printf("-------------------------\n",indx2[tempindx],rank);
683         }
684      }
685 
686       ierr = ISCreateGeneral(comm,local_n0*dim[1]*dim[2],indx1,PETSC_COPY_VALUES,&list1);CHKERRQ(ierr);
687       ierr = ISCreateGeneral(comm,local_n0*dim[1]*dim[2],indx2,PETSC_COPY_VALUES,&list2);CHKERRQ(ierr);
688 
689       ierr = VecScatterCreate(x,list1,y,list2,&vecscat);CHKERRQ(ierr);
690       ierr = VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
691       ierr = VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
692       ierr = VecScatterDestroy(&vecscat);CHKERRQ(ierr);
693       break;
694 
695  default:
696   SETERRQ(comm,PETSC_ERR_SUP,"Not Done Yet");
697   break;
698  }
699 
700  return 0;
701 }
702 EXTERN_C_END
703 
704 #undef __FUNCT__
705 #define __FUNCT__ "OutputTransformFFT"
706 PetscErrorCode OutputTransformFFT(Mat A,Vec x,Vec y)
707 {
708   PetscErrorCode ierr;
709   PetscFunctionBegin;
710   ierr = PetscTryMethod(A,"OutputTransformFFT_C",(Mat,Vec,Vec),(A,x,y));CHKERRQ(ierr);
711   PetscFunctionReturn(0);
712 }
713 
714 /*
715       OutputTransformFFT_FFTW - Copies the FFTW output to the PETSc vector that user can use
716   Input A, x, y
717   A - FFTW matrix
718   x - FFTW vector
719   y - PETSc vector that user can read
720   Options Database Keys:
721 + -mat_fftw_plannerflags - set FFTW planner flags
722 
723    Level: intermediate
724 
725 */
726 
727 EXTERN_C_BEGIN
728 #undef __FUNCT__
729 #define __FUNCT__ "OutputTransformFFT_FTTW"
730 PetscErrorCode OutputTransformFFT_FFTW(Mat A,Vec x,Vec y)
731 {
732   PetscErrorCode ierr;
733   MPI_Comm       comm=((PetscObject)A)->comm;
734   Mat_FFT        *fft = (Mat_FFT*)A->data;
735   Mat_FFTW       *fftw = (Mat_FFTW*)fft->data;
736   PetscInt       N=fft->N, N1, n1 ,NM;
737   PetscInt       ndim=fft->ndim,*dim=fft->dim,n=fft->n;
738   PetscInt       low, *indx1, *indx2, tempindx, tempindx1, *indx3, *indx4;
739   PetscInt       i,j,k,rank,size;
740   ptrdiff_t      alloc_local,local_n0,local_0_start;
741   ptrdiff_t      local_n1,local_1_start;
742   VecScatter     vecscat;
743   IS             list1,list2;
744 
745   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
746   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
747   ierr = VecGetOwnershipRange(x,&low,PETSC_NULL);
748   printf("Local ownership starts at %d\n",low);
749 
750  switch (ndim){
751  case 1:
752   SETERRQ(comm,PETSC_ERR_SUP,"Not Supported by FFTW");
753   break;
754  case 2:
755       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);
756       N1 = 2*dim[0]*(dim[1]/2+1); n1 = 2*local_n0*(dim[1]/2+1);
757 
758      ierr = PetscMalloc(sizeof(PetscInt)*((PetscInt)local_n0)*N1,&indx1);CHKERRQ(ierr);
759      ierr = PetscMalloc(sizeof(PetscInt)*((PetscInt)local_n0)*N1,&indx2);CHKERRQ(ierr);
760      printf("Val local_0_start = %ld\n",local_0_start);
761 
762      if (dim[1]%2==0)
763       NM = dim[1]+2;
764     else
765       NM = dim[1]+1;
766 
767 
768 
769      for (i=0;i<local_n0;i++){
770         for (j=0;j<dim[1];j++){
771             tempindx = i*dim[1] + j;
772             tempindx1 = i*NM + j;
773             indx1[tempindx]=local_0_start*dim[1]+tempindx;
774             indx2[tempindx]=low+tempindx1;
775        //     printf("Val tempindx1 = %d\n",tempindx1);
776        //     printf("index1 %d from proc %d is \n",indx1[tempindx],rank);
777        //     printf("index2 %d from proc %d is \n",indx2[tempindx],rank);
778        //     printf("-------------------------\n",indx2[tempindx],rank);
779         }
780      }
781 
782      ierr = ISCreateGeneral(comm,local_n0*dim[1],indx1,PETSC_COPY_VALUES,&list1);CHKERRQ(ierr);
783      ierr = ISCreateGeneral(comm,local_n0*dim[1],indx2,PETSC_COPY_VALUES,&list2);CHKERRQ(ierr);
784 
785      ierr = VecScatterCreate(x,list2,y,list1,&vecscat);CHKERRQ(ierr);
786      ierr = VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
787      ierr = VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
788      ierr = VecScatterDestroy(&vecscat);CHKERRQ(ierr);
789   break;
790 
791  case 3:
792       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);
793       N1 = 2*dim[0]*dim[1]*(dim[2]/2+1); n1 = 2*local_n0*dim[1]*(dim[2]/2+1);
794 
795      ierr = PetscMalloc(sizeof(PetscInt)*((PetscInt)local_n0)*N1,&indx1);CHKERRQ(ierr);
796      ierr = PetscMalloc(sizeof(PetscInt)*((PetscInt)local_n0)*N1,&indx2);CHKERRQ(ierr);
797      printf("Val local_0_start = %ld\n",local_0_start);
798 
799      if (dim[2]%2==0)
800       NM = dim[2]+2;
801     else
802       NM = dim[2]+1;
803 
804      for (i=0;i<local_n0;i++){
805         for (j=0;j<dim[1];j++){
806            for (k=0;k<dim[2];k++){
807               tempindx = i*dim[1]*dim[2] + j*dim[2] + k;
808               tempindx1 = i*dim[1]*NM + j*NM + k;
809               indx1[tempindx]=local_0_start*dim[1]*dim[2]+tempindx;
810               indx2[tempindx]=low+tempindx1;
811            }
812         //    printf("Val tempindx1 = %d\n",tempindx1);
813         //    printf("index1 %d from proc %d is \n",indx1[tempindx],rank);
814         //    printf("index2 %d from proc %d is \n",indx2[tempindx],rank);
815         //    printf("-------------------------\n",indx2[tempindx],rank);
816         }
817      }
818 
819      ierr = ISCreateGeneral(comm,local_n0*dim[1]*dim[2],indx1,PETSC_COPY_VALUES,&list1);CHKERRQ(ierr);
820      ierr = ISCreateGeneral(comm,local_n0*dim[1]*dim[2],indx2,PETSC_COPY_VALUES,&list2);CHKERRQ(ierr);
821 
822      ierr = VecScatterCreate(x,list2,y,list1,&vecscat);CHKERRQ(ierr);
823      ierr = VecScatterBegin(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
824      ierr = VecScatterEnd(vecscat,x,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
825      ierr = VecScatterDestroy(&vecscat);CHKERRQ(ierr);
826   break;
827 
828  default:
829   SETERRQ(comm,PETSC_ERR_SUP,"Not Done Yet");
830   break;
831  }
832  return 0;
833 }
834 EXTERN_C_END
835 
836 EXTERN_C_BEGIN
837 #undef __FUNCT__
838 #define __FUNCT__ "MatCreate_FFTW"
839 /*
840       MatCreate_FFTW - Creates a matrix object that provides FFT
841   via the external package FFTW
842   Options Database Keys:
843 + -mat_fftw_plannerflags - set FFTW planner flags
844 
845    Level: intermediate
846 
847 */
848 
849 PetscErrorCode MatCreate_FFTW(Mat A)
850 {
851   PetscErrorCode ierr;
852   MPI_Comm       comm=((PetscObject)A)->comm;
853   Mat_FFT        *fft=(Mat_FFT*)A->data;
854   Mat_FFTW       *fftw;
855   PetscInt       n=fft->n,N=fft->N,ndim=fft->ndim,*dim = fft->dim;
856   const char     *p_flags[]={"FFTW_ESTIMATE","FFTW_MEASURE","FFTW_PATIENT","FFTW_EXHAUSTIVE"};
857   PetscBool      flg;
858   PetscInt       p_flag,partial_dim=1,ctr;
859   PetscMPIInt    size,rank;
860   ptrdiff_t      *pdim;
861   ptrdiff_t      local_n1,local_1_start;
862 
863   PetscFunctionBegin;
864 //#if !defined(PETSC_USE_COMPLEX)
865 //  SETERRQ(comm,PETSC_ERR_SUP,"not support for real numbers");
866 //#endif
867 
868   ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
869   ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
870   ierr = MPI_Barrier(PETSC_COMM_WORLD);
871 
872   pdim = (ptrdiff_t *)calloc(ndim,sizeof(ptrdiff_t));
873   pdim[0] = dim[0];
874   for(ctr=1;ctr<ndim;ctr++)
875       {
876           partial_dim *= dim[ctr];
877           pdim[ctr] = dim[ctr];
878       }
879 //#if !defined(PETSC_USE_COMPLEX)
880 //  SETERRQ(comm,PETSC_ERR_SUP,"not support for real numbers");
881 //#endif
882 
883 //  printf("partial dimension is %d",partial_dim);
884   if (size == 1) {
885     ierr = MatSetSizes(A,N,N,N,N);CHKERRQ(ierr);
886     n = N;
887   } else {
888     ptrdiff_t alloc_local,local_n0,local_0_start,local_n1,local_1_end;
889     switch (ndim){
890     case 1:
891 #if !defined(PETSC_USE_COMPLEX)
892   SETERRQ(comm,PETSC_ERR_SUP,"FFTW does not support parallel 1D real transform");
893 #endif
894       alloc_local = fftw_mpi_local_size_1d(dim[0],comm,FFTW_FORWARD,FFTW_ESTIMATE,&local_n0,&local_0_start,&local_n1,&local_1_end);
895       n = (PetscInt)local_n0;
896       ierr = MatSetSizes(A,n,n,N,N);CHKERRQ(ierr);
897 //      PetscObjectComposeFunctionDynamic((PetscObject)A,"MatGetVecs1DC_C","MatGetVecs1DC_FFTW",MatGetVecs1DC_FFTW);
898       break;
899     case 2:
900 #if defined(PETSC_USE_COMPLEX)
901       alloc_local = fftw_mpi_local_size_2d(dim[0],dim[1],comm,&local_n0,&local_0_start);
902       /*
903        PetscMPIInt    rank;
904        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]);
905        PetscSynchronizedFlush(comm);
906        */
907       n = (PetscInt)local_n0*dim[1];
908       ierr = MatSetSizes(A,n,n,N,N);CHKERRQ(ierr);
909 #else
910       alloc_local = fftw_mpi_local_size_2d_transposed(dim[0],dim[1]/2+1,PETSC_COMM_WORLD,&local_n0,&local_0_start,&local_n1,&local_1_start);
911       n = 2*(PetscInt)local_n0*(dim[1]/2+1);
912       ierr = MatSetSizes(A,n,n,2*dim[0]*(dim[1]/2+1),2*dim[0]*(dim[1]/2+1));
913 #endif
914       break;
915     case 3:
916 //      printf("The value of alloc local is %d",alloc_local);
917 #if defined(PETSC_USE_COMPLEX)
918       alloc_local = fftw_mpi_local_size_3d(dim[0],dim[1],dim[2],comm,&local_n0,&local_0_start);
919       n = (PetscInt)local_n0*dim[1]*dim[2];
920       ierr = MatSetSizes(A,n,n,N,N);CHKERRQ(ierr);
921 #else
922       printf("The code comes here\n");
923       alloc_local = fftw_mpi_local_size_3d_transposed(dim[0],dim[1],dim[2]/2+1,PETSC_COMM_WORLD,&local_n0,&local_0_start,&local_n1,&local_1_start);
924       n = 2*(PetscInt)local_n0*dim[1]*(dim[2]/2+1);
925       ierr = MatSetSizes(A,n,n,2*dim[0]*dim[1]*(dim[2]/2+1),2*dim[0]*dim[1]*(dim[2]/2+1));
926 #endif
927       break;
928     default:
929       alloc_local = fftw_mpi_local_size(ndim,pdim,comm,&local_n0,&local_0_start);
930 //      printf("The value of alloc local is %ld from process %d\n",alloc_local,rank);
931 //      alloc_local = fftw_mpi_local_size(ndim,dim,comm,&local_n0,&local_0_start);
932       n = (PetscInt)local_n0*partial_dim;
933 //      printf("New partial dimension is %d %d %d",n,N,ndim);
934       ierr = MatSetSizes(A,n,n,N,N);CHKERRQ(ierr);
935       break;
936     }
937   }
938   ierr = PetscObjectChangeTypeName((PetscObject)A,MATFFTW);CHKERRQ(ierr);
939 
940   ierr = PetscNewLog(A,Mat_FFTW,&fftw);CHKERRQ(ierr);
941   fft->data = (void*)fftw;
942 
943   fft->n           = n;
944   fftw->ndim_fftw  = (ptrdiff_t)ndim; // This is dimension of fft
945   ierr = PetscMalloc(ndim*sizeof(ptrdiff_t), (ptrdiff_t *)&(fftw->dim_fftw));CHKERRQ(ierr);
946   for(ctr=0;ctr<ndim;ctr++) (fftw->dim_fftw)[ctr]=dim[ctr];
947 
948   fftw->p_forward  = 0;
949   fftw->p_backward = 0;
950   fftw->p_flag     = FFTW_ESTIMATE;
951 
952   if (size == 1){
953     A->ops->mult          = MatMult_SeqFFTW;
954     A->ops->multtranspose = MatMultTranspose_SeqFFTW;
955   } else {
956     A->ops->mult          = MatMult_MPIFFTW;
957     A->ops->multtranspose = MatMultTranspose_MPIFFTW;
958   }
959   fft->matdestroy          = MatDestroy_FFTW;
960   A->ops->getvecs       = MatGetVecs_FFTW;
961   A->assembled          = PETSC_TRUE;
962 #if !defined(PETSC_USE_COMPLEX)
963   PetscObjectComposeFunctionDynamic((PetscObject)A,"InputTransformFFT_C","InputTransformFFT_FFTW",InputTransformFFT_FFTW);
964   PetscObjectComposeFunctionDynamic((PetscObject)A,"OutputTransformFFT_C","OutputTransformFFT_FFTW",OutputTransformFFT_FFTW);
965 #endif
966 
967   /* get runtime options */
968   ierr = PetscOptionsBegin(((PetscObject)A)->comm,((PetscObject)A)->prefix,"FFTW Options","Mat");CHKERRQ(ierr);
969     ierr = PetscOptionsEList("-mat_fftw_plannerflags","Planner Flags","None",p_flags,4,p_flags[0],&p_flag,&flg);CHKERRQ(ierr);
970     if (flg) {fftw->p_flag = (unsigned)p_flag;}
971   PetscOptionsEnd();
972   PetscFunctionReturn(0);
973 }
974 EXTERN_C_END
975 
976 
977 
978 
979