Actual source code: isdiff.c
2: #include <petscis.h> /*I "petscis.h" I*/
3: #include <petscbt.h>
7: /*@
8: ISDifference - Computes the difference between two index sets.
10: Collective on IS
12: Input Parameter:
13: + is1 - first index, to have items removed from it
14: - is2 - index values to be removed
16: Output Parameters:
17: . isout - is1 - is2
19: Notes:
20: Negative values are removed from the lists. is2 may have values
21: that are not in is1. This requires O(imax-imin) memory and O(imax-imin)
22: work, where imin and imax are the bounds on the indices in is1.
24: Level: intermediate
26: Concepts: index sets^difference
27: Concepts: IS^difference
29: .seealso: ISDestroy(), ISView(), ISSum(), ISExpand()
31: @*/
32: PetscErrorCode ISDifference(IS is1,IS is2,IS *isout)
33: {
35: PetscInt i,n1,n2,imin,imax,nout,*iout;
36: const PetscInt *i1,*i2;
37: PetscBT mask;
38: MPI_Comm comm;
45: ISGetIndices(is1,&i1);
46: ISGetLocalSize(is1,&n1);
48: /* Create a bit mask array to contain required values */
49: if (n1) {
50: imin = PETSC_MAX_INT;
51: imax = 0;
52: for (i=0; i<n1; i++) {
53: if (i1[i] < 0) continue;
54: imin = PetscMin(imin,i1[i]);
55: imax = PetscMax(imax,i1[i]);
56: }
57: } else {
58: imin = imax = 0;
59: }
60: PetscBTCreate(imax-imin,mask);
61: /* Put the values from is1 */
62: for (i=0; i<n1; i++) {
63: if (i1[i] < 0) continue;
64: PetscBTSet(mask,i1[i] - imin);
65: }
66: ISRestoreIndices(is1,&i1);
67: /* Remove the values from is2 */
68: ISGetIndices(is2,&i2);
69: ISGetLocalSize(is2,&n2);
70: for (i=0; i<n2; i++) {
71: if (i2[i] < imin || i2[i] > imax) continue;
72: PetscBTClear(mask,i2[i] - imin);
73: }
74: ISRestoreIndices(is2,&i2);
75:
76: /* Count the number in the difference */
77: nout = 0;
78: for (i=0; i<imax-imin+1; i++) {
79: if (PetscBTLookup(mask,i)) nout++;
80: }
82: /* create the new IS containing the difference */
83: PetscMalloc(nout*sizeof(PetscInt),&iout);
84: nout = 0;
85: for (i=0; i<imax-imin+1; i++) {
86: if (PetscBTLookup(mask,i)) iout[nout++] = i + imin;
87: }
88: PetscObjectGetComm((PetscObject)is1,&comm);
89: ISCreateGeneral(comm,nout,iout,PETSC_OWN_POINTER,isout);
91: PetscBTDestroy(mask);
92: return(0);
93: }
97: /*@
98: ISSum - Computes the sum (union) of two index sets.
100: Only sequential version (at the moment)
102: Input Parameter:
103: + is1 - index set to be extended
104: - is2 - index values to be added
106: Output Parameter:
107: . is3 - the sum; this can not be is1 or is2
109: Notes:
110: If n1 and n2 are the sizes of the sets, this takes O(n1+n2) time;
112: Both index sets need to be sorted on input.
114: Level: intermediate
116: .seealso: ISDestroy(), ISView(), ISDifference(), ISExpand()
118: Concepts: index sets^union
119: Concepts: IS^union
121: @*/
122: PetscErrorCode ISSum(IS is1,IS is2,IS *is3)
123: {
124: MPI_Comm comm;
125: PetscBool f;
126: PetscMPIInt size;
127: const PetscInt *i1,*i2;
128: PetscInt n1,n2,n3, p1,p2, *iout;
134: PetscObjectGetComm((PetscObject)(is1),&comm);
135: MPI_Comm_size(comm,&size);
136: if (size>1) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Currently only for uni-processor IS");
138: ISSorted(is1,&f);
139: if (!f) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Arg 1 is not sorted");
140: ISSorted(is2,&f);
141: if (!f) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Arg 2 is not sorted");
143: ISGetLocalSize(is1,&n1);
144: ISGetLocalSize(is2,&n2);
145: if (!n2) return(0);
146: ISGetIndices(is1,&i1);
147: ISGetIndices(is2,&i2);
149: p1 = 0; p2 = 0; n3 = 0;
150: do {
151: if (p1==n1) { /* cleanup for is2 */ n3 += n2-p2; break;
152: } else {
153: while (p2<n2 && i2[p2]<i1[p1]) {n3++; p2++;}
154: if (p2==n2) { /* cleanup for is1 */ n3 += n1-p1; break;
155: } else {
156: if (i2[p2]==i1[p1]) {n3++; p1++; p2++;}
157: }
158: }
159: if (p2==n2) { /* cleanup for is1 */ n3 += n1-p1; break;
160: } else {
161: while (p1<n1 && i1[p1]<i2[p2]) {n3++; p1++;}
162: if (p1==n1) { /* clean up for is2 */ n3 += n2-p2; break;
163: } else {
164: if (i1[p1]==i2[p2]) {n3++; p1++; p2++;}
165: }
166: }
167: } while (p1<n1 || p2<n2);
169: if (n3==n1) { /* no new elements to be added */
170: ISRestoreIndices(is1,&i1);
171: ISRestoreIndices(is2,&i2);
172: ISDuplicate(is1,is3);
173: return(0);
174: }
175: PetscMalloc(n3*sizeof(PetscInt),&iout);
177: p1 = 0; p2 = 0; n3 = 0;
178: do {
179: if (p1==n1) { /* cleanup for is2 */
180: while (p2<n2) iout[n3++] = i2[p2++];
181: break;
182: } else {
183: while (p2<n2 && i2[p2]<i1[p1]) iout[n3++] = i2[p2++];
184: if (p2==n2) { /* cleanup for is1 */
185: while (p1<n1) iout[n3++] = i1[p1++];
186: break;
187: } else {
188: if (i2[p2]==i1[p1]) {iout[n3++] = i1[p1++]; p2++;}
189: }
190: }
191: if (p2==n2) { /* cleanup for is1 */
192: while (p1<n1) iout[n3++] = i1[p1++];
193: break;
194: } else {
195: while (p1<n1 && i1[p1]<i2[p2]) iout[n3++] = i1[p1++];
196: if (p1==n1) { /* clean up for is2 */
197: while (p2<n2) iout[n3++] = i2[p2++];
198: break;
199: } else {
200: if (i1[p1]==i2[p2]) {iout[n3++] = i1[p1++]; p2++;}
201: }
202: }
203: } while (p1<n1 || p2<n2);
205: ISRestoreIndices(is1,&i1);
206: ISRestoreIndices(is2,&i2);
207: ISCreateGeneral(comm,n3,iout,PETSC_OWN_POINTER,is3);
208: return(0);
209: }
213: /*@
214: ISExpand - Computes the union of two index sets, by concatenating 2 lists and
215: removing duplicates.
217: Collective on IS
219: Input Parameter:
220: + is1 - first index set
221: - is2 - index values to be added
223: Output Parameters:
224: . isout - is1 + is2 The index set is2 is appended to is1 removing duplicates
226: Notes:
227: Negative values are removed from the lists. This requires O(imax-imin)
228: memory and O(imax-imin) work, where imin and imax are the bounds on the
229: indices in is1 and is2.
231: The IS's do not need to be sorted.
233: Level: intermediate
235: .seealso: ISDestroy(), ISView(), ISDifference(), ISSum()
237: Concepts: index sets^difference
238: Concepts: IS^difference
240: @*/
241: PetscErrorCode ISExpand(IS is1,IS is2,IS *isout)
242: {
244: PetscInt i,n1,n2,imin,imax,nout,*iout;
245: const PetscInt *i1,*i2;
246: PetscBT mask;
247: MPI_Comm comm;
254: ISGetIndices(is1,&i1);
255: ISGetLocalSize(is1,&n1);
256: ISGetIndices(is2,&i2);
257: ISGetLocalSize(is2,&n2);
259: /* Create a bit mask array to contain required values */
260: if (n1 || n2) {
261: imin = PETSC_MAX_INT;
262: imax = 0;
263: for (i=0; i<n1; i++) {
264: if (i1[i] < 0) continue;
265: imin = PetscMin(imin,i1[i]);
266: imax = PetscMax(imax,i1[i]);
267: }
268: for (i=0; i<n2; i++) {
269: if (i2[i] < 0) continue;
270: imin = PetscMin(imin,i2[i]);
271: imax = PetscMax(imax,i2[i]);
272: }
273: } else {
274: imin = imax = 0;
275: }
276: PetscMalloc((n1+n2)*sizeof(PetscInt),&iout);
277: nout = 0;
278: PetscBTCreate(imax-imin,mask);
279: /* Put the values from is1 */
280: for (i=0; i<n1; i++) {
281: if (i1[i] < 0) continue;
282: if (!PetscBTLookupSet(mask,i1[i] - imin)) {
283: iout[nout++] = i1[i];
284: }
285: }
286: ISRestoreIndices(is1,&i1);
287: /* Put the values from is2 */
288: for (i=0; i<n2; i++) {
289: if (i2[i] < 0) continue;
290: if (!PetscBTLookupSet(mask,i2[i] - imin)) {
291: iout[nout++] = i2[i];
292: }
293: }
294: ISRestoreIndices(is2,&i2);
296: /* create the new IS containing the sum */
297: PetscObjectGetComm((PetscObject)is1,&comm);
298: ISCreateGeneral(comm,nout,iout,PETSC_OWN_POINTER,isout);
300: PetscBTDestroy(mask);
301: return(0);
302: }