Actual source code: matusfft.c
petsc-3.3-p5 2012-12-01
2: /*
3: Provides an implementation of the Unevenly Sampled FFT algorithm as a Mat.
4: Testing examples can be found in ~/src/mat/examples/tests FIX: should these be moved to dm/da/examples/tests?
5: */
7: #include <petsc-private/matimpl.h> /*I "petscmat.h" I*/
8: #include <petscdmda.h> /*I "petscdmda.h" I*/ /* Unlike equispaced FFT, USFFT requires geometric information encoded by a DMDA */
9: #include <fftw3.h>
11: typedef struct {
12: PetscInt dim;
13: Vec sampleCoords;
14: PetscInt dof;
15: DM freqDA; /* frequency DMDA */
16: PetscInt *freqSizes; /* sizes of the frequency DMDA, one per each dim */
17: DM resampleDa; /* the Battle-Lemarie interpolant DMDA */
18: Vec resample; /* Vec of samples, one per dof per sample point */
19: fftw_plan p_forward,p_backward;
20: unsigned p_flag; /* planner flags, FFTW_ESTIMATE,FFTW_MEASURE, FFTW_PATIENT, FFTW_EXHAUSTIVE */
21: } Mat_USFFT;
26: PetscErrorCode MatApply_USFFT_Private(Mat A, fftw_plan *plan, int direction, Vec x,Vec y)
27: {
28: #if 0
30: PetscScalar *r_array, *y_array;
31: Mat_USFFT* = (Mat_USFFT*)(A->data);
32: #endif
35: #if 0
36: /* resample x to usfft->resample */
37: MatResample_USFFT_Private(A, x);
39: /* NB: for now we use outdim for both x and y; this will change once a full USFFT is implemented */
40: VecGetArray(usfft->resample,&r_array);
41: VecGetArray(y,&y_array);
42: if (!*plan){ /* create a plan then execute it*/
43: if(usfft->dof == 1) {
44: #ifdef PETSC_DEBUG_USFFT
45: PetscPrintf(((PetscObject)A)->comm, "direction = %d, usfft->ndim = %d\n", direction, usfft->ndim);
46: for(int ii = 0; ii < usfft->ndim; ++ii) {
47: PetscPrintf(((PetscObject)A)->comm, "usfft->outdim[%d] = %d\n", ii, usfft->outdim[ii]);
48: }
49: #endif
51: switch (usfft->dim){
52: case 1:
53: *plan = fftw_plan_dft_1d(usfft->outdim[0],(fftw_complex*)x_array,(fftw_complex*)y_array,direction,usfft->p_flag);
54: break;
55: case 2:
56: *plan = fftw_plan_dft_2d(usfft->outdim[0],usfft->outdim[1],(fftw_complex*)x_array,(fftw_complex*)y_array,direction,usfft->p_flag);
57: break;
58: case 3:
59: *plan = fftw_plan_dft_3d(usfft->outdim[0],usfft->outdim[1],usfft->outdim[2],(fftw_complex*)x_array,(fftw_complex*)y_array,direction,usfft->p_flag);
60: break;
61: default:
62: *plan = fftw_plan_dft(usfft->ndim,usfft->outdim,(fftw_complex*)x_array,(fftw_complex*)y_array,direction,usfft->p_flag);
63: break;
64: }
65: fftw_execute(*plan);
66: }/* if(dof == 1) */
67: else { /* if(dof > 1) */
68: *plan = fftw_plan_many_dft(/*rank*/usfft->ndim, /*n*/usfft->outdim, /*howmany*/usfft->dof,
69: (fftw_complex*)x_array, /*nembed*/usfft->outdim, /*stride*/usfft->dof, /*dist*/1,
70: (fftw_complex*)y_array, /*nembed*/usfft->outdim, /*stride*/usfft->dof, /*dist*/1,
71: /*sign*/direction, /*flags*/usfft->p_flag);
72: fftw_execute(*plan);
73: }/* if(dof > 1) */
74: }/* if(!*plan) */
75: else { /* if(*plan) */
76: /* use existing plan */
77: fftw_execute_dft(*plan,(fftw_complex*)x_array,(fftw_complex*)y_array);
78: }
79: VecRestoreArray(y,&y_array);
80: VecRestoreArray(x,&x_array);
81: #endif
82: return(0);
83: }/* MatApply_USFFT_Private() */
85: #if 0
88: PetscErrorCode Mat_USFFT_ProjectOnBattleLemarie_Private(Vec x,double *r)
89: /* Project onto the Battle-Lemarie function centered around r */
90: {
92: PetscScalar *x_array, *y_array;
95: return(0);
96: }/* Mat_USFFT_ProjectOnBattleLemarie_Private() */
100: PetscErrorCode MatInterpolate_USFFT_Private(Vec x,Vec y)
101: {
103: PetscScalar *x_array, *y_array;
106: return(0);
107: }/* MatInterpolate_USFFT_Private() */
112: PetscErrorCode MatMult_SeqUSFFT(Mat A,Vec x,Vec y)
113: {
115: Mat_USFFT *usfft = (Mat_USFFT*)A->data;
118: /* NB: for now we use outdim for both x and y; this will change once a full USFFT is implemented */
119: MatApply_USFFT_Private(A, &usfft->p_forward, FFTW_FORWARD, x,y);
120: return(0);
121: }
125: PetscErrorCode MatMultTranspose_SeqUSFFT(Mat A,Vec x,Vec y)
126: {
128: Mat_USFFT *usfft = (Mat_USFFT*)A->data;
130: /* NB: for now we use outdim for both x and y; this will change once a full USFFT is implemented */
131: MatApply_USFFT_Private(usfft, &usfft->p_backward, FFTW_BACKWARD, x,y);
132: return(0);
133: }
137: PetscErrorCode MatDestroy_SeqUSFFT(Mat A)
138: {
139: Mat_USFFT *usfft = (Mat_USFFT*)A->data;
143: fftw_destroy_plan(usfft->p_forward);
144: fftw_destroy_plan(usfft->p_backward);
145: PetscFree(usfft->indim);
146: PetscFree(usfft->outdim);
147: PetscFree(usfft);
148: PetscObjectChangeTypeName((PetscObject)A,0);
149: return(0);
150: }/* MatDestroy_SeqUSFFT() */
155: /*@C
156: MatCreateSeqUSFFT - Creates a matrix object that provides sequential USFFT
157: via the external package FFTW
159: Collective on MPI_Comm
161: Input Parameter:
162: + da - geometry of the domain encoded by a DMDA
164: Output Parameter:
165: . A - the matrix
167: Options Database Keys:
168: + -mat_usfft_plannerflags - set the FFTW planner flags
170: Level: intermediate
171:
172: @*/
173: PetscErrorCode MatCreateSeqUSFFT(Vec sampleCoords, DMDA freqDA, Mat* A)
174: {
176: Mat_USFFT *usfft;
177: PetscInt m,n,M,N,i;
178: const char *p_flags[]={"FFTW_ESTIMATE","FFTW_MEASURE","FFTW_PATIENT","FFTW_EXHAUSTIVE"};
179: PetscBool flg;
180: PetscInt p_flag;
181: PetscInt dof, dim, freqSizes[3];
182: MPI_Comm comm;
183: PetscInt size;
186: PetscObjectGetComm((PetscObject)inda, &comm);
187: MPI_Comm_size(comm, &size);
188: if (size > 1) SETERRQ(comm,PETSC_ERR_USER, "Parallel DMDA (in) not yet supported by USFFT");
189: PetscObjectGetComm((PetscObject)outda, &comm);
190: MPI_Comm_size(comm, &size);
191: if (size > 1) SETERRQ(comm,PETSC_ERR_USER, "Parallel DMDA (out) not yet supported by USFFT");
192: MatCreate(comm,A);
193: PetscNewLog(*A,Mat_USFFT,&usfft);
194: (*A)->data = (void*)usfft;
195: usfft->inda = inda;
196: usfft->outda = outda;
197: /* inda */
198: DMDAGetInfo(usfft->inda, &ndim, dim+0, dim+1, dim+2, PETSC_NULL, PETSC_NULL, PETSC_NULL, &dof, PETSC_NULL, PETSC_NULL, PETSC_NULL);
199: if (ndim <= 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_USER,"ndim %d must be > 0",ndim);
200: if (dof <= 0) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_USER,"dof %d must be > 0",dof);
201: usfft->ndim = ndim;
202: usfft->dof = dof;
203: usfft->freqDA = freqDA;
204: /* NB: we reverse the freq and resample DMDA sizes, since the DMDA ordering (natural on x-y-z, with x varying the fastest)
205: is the order opposite of that assumed by FFTW: z varying the fastest */
206: PetscMalloc((usfft->ndim+1)*sizeof(PetscInt),&usfft->indim);
207: for(i = usfft->ndim; i > 0; --i) {
208: usfft->indim[usfft->ndim-i] = dim[i-1];
209: }
210: /* outda */
211: DMDAGetInfo(usfft->outda, &ndim, dim+0, dim+1, dim+2, PETSC_NULL, PETSC_NULL, PETSC_NULL, &dof, PETSC_NULL, PETSC_NULL, PETSC_NULL);
212: if (ndim != usfft->ndim) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_USER,"in and out DMDA dimensions must match: %d != %d",usfft->ndim, ndim);
213: if (dof != usfft->dof) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_USER,"in and out DMDA dof must match: %d != %d",usfft->dof, dof);
214: /* Store output dimensions */
215: /* NB: we reverse the DMDA dimensions, since the DMDA ordering (natural on x-y-z, with x varying the fastest)
216: is the order opposite of that assumed by FFTW: z varying the fastest */
217: PetscMalloc((usfft->ndim+1)*sizeof(PetscInt),&usfft->outdim);
218: for(i = usfft->ndim; i > 0; --i) {
219: usfft->outdim[usfft->ndim-i] = dim[i-1];
220: }
222: /* TODO: Use the new form of DMDACreate() */
223: #if 0
224: DMDACreate(comm,usfft->dim, DMDA_NONPERIODIC, DMDA_STENCIL_STAR, usfft->freqSizes[0], usfft->freqSizes[1], usfft->freqSizes[2],
225: PETSC_DECIDE, PETSC_DECIDE, PETSC_DECIDE, dof, 0, PETSC_NULL, PETSC_NULL, PETSC_NULL, 0, &(usfft->resampleDA));
226: #endif
227: DMDAGetVec(usfft->resampleDA, usfft->resample);
230: /* CONTINUE: Need to build the connectivity "Sieve" attaching sample points to the resample points they are close to */
232: /* CONTINUE: recalculate matrix sizes based on the connectivity "Sieve" */
233: /* mat sizes */
234: m = 1; n = 1;
235: for (i=0; i<usfft->ndim; i++){
236: if (usfft->indim[i] <= 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_USER,"indim[%d]=%d must be > 0",i,usfft->indim[i]);
237: if (usfft->outdim[i] <= 0) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_USER,"outdim[%d]=%d must be > 0",i,usfft->outdim[i]);
238: n *= usfft->indim[i];
239: m *= usfft->outdim[i];
240: }
241: N = n*usfft->dof;
242: M = m*usfft->dof;
243: MatSetSizes(*A,M,N,M,N); /* "in size" is the number of columns, "out size" is the number of rows" */
244: PetscObjectChangeTypeName((PetscObject)*A,MATSEQUSFFT);
245: usfft->m = m; usfft->n = n; usfft->M = M; usfft->N = N;
246: /* FFTW */
247: usfft->p_forward = 0;
248: usfft->p_backward = 0;
249: usfft->p_flag = FFTW_ESTIMATE;
250: /* set Mat ops */
251: (*A)->ops->mult = MatMult_SeqUSFFT;
252: (*A)->ops->multtranspose = MatMultTranspose_SeqUSFFT;
253: (*A)->assembled = PETSC_TRUE;
254: (*A)->ops->destroy = MatDestroy_SeqUSFFT;
255: /* get runtime options */
256: PetscOptionsBegin(((PetscObject)(*A))->comm,((PetscObject)(*A))->prefix,"USFFT Options","Mat");
257: PetscOptionsEList("-mat_usfft_fftw_plannerflags","Planner Flags","None",p_flags,4,p_flags[0],&p_flag,&flg);
258: if (flg) {usfft->p_flag = (unsigned)p_flag;}
259: PetscOptionsEnd();
260: return(0);
261: }/* MatCreateSeqUSFFT() */
263: #endif