Actual source code: rgpolygon.c

slepc-3.11.2 2019-07-30
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2019, Universitat Politecnica de Valencia, Spain

  6:    This file is part of SLEPc.
  7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
  8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  9: */
 10: /*
 11:    Polygonal region defined by a set of vertices
 12: */

 14: #include <slepc/private/rgimpl.h>      /*I "slepcrg.h" I*/
 15: #include <petscdraw.h>

 17: #define VERTMAX 30

 19: typedef struct {
 20:   PetscInt    n;         /* number of vertices */
 21:   PetscScalar *vr,*vi;   /* array of vertices (vi not used in complex scalars) */
 22: } RG_POLYGON;

 24: PetscErrorCode RGComputeBoundingBox_Polygon(RG,PetscReal*,PetscReal*,PetscReal*,PetscReal*);

 26: #if !defined(PETSC_USE_COMPLEX)
 27: static PetscBool CheckSymmetry(PetscInt n,PetscScalar *vr,PetscScalar *vi)
 28: {
 29:   PetscInt i,j,k;
 30:   /* find change of sign in imaginary part */
 31:   j = vi[0]!=0.0? 0: 1;
 32:   for (k=j+1;k<n;k++) {
 33:     if (vi[k]!=0.0) {
 34:       if (vi[k]*vi[j]<0.0) break;
 35:       j++;
 36:     }
 37:   }
 38:   if (k==n) return (j==1)? PETSC_TRUE: PETSC_FALSE;
 39:   /* check pairing vertices */
 40:   for (i=0;i<n/2;i++) {
 41:     if (vr[k]!=vr[j] || vi[k]!=-vi[j]) return PETSC_FALSE;
 42:     k = (k+1)%n;
 43:     j = (j-1+n)%n;
 44:   }
 45:   return PETSC_TRUE;
 46: }
 47: #endif

 49: static PetscErrorCode RGPolygonSetVertices_Polygon(RG rg,PetscInt n,PetscScalar *vr,PetscScalar *vi)
 50: {
 52:   PetscInt       i;
 53:   RG_POLYGON     *ctx = (RG_POLYGON*)rg->data;

 56:   if (n<3) SETERRQ1(PetscObjectComm((PetscObject)rg),PETSC_ERR_ARG_OUTOFRANGE,"At least 3 vertices required, you provided %s",n);
 57:   if (n>VERTMAX) SETERRQ1(PetscObjectComm((PetscObject)rg),PETSC_ERR_ARG_OUTOFRANGE,"Too many points, maximum allowed is %d",VERTMAX);
 58: #if !defined(PETSC_USE_COMPLEX)
 59:   if (!CheckSymmetry(n,vr,vi)) SETERRQ(PetscObjectComm((PetscObject)rg),PETSC_ERR_ARG_WRONG,"In real scalars the region must be symmetric wrt real axis");
 60: #endif
 61:   if (ctx->n) {
 62:     PetscFree(ctx->vr);
 63: #if !defined(PETSC_USE_COMPLEX)
 64:     PetscFree(ctx->vi);
 65: #endif
 66:   }
 67:   ctx->n = n;
 68:   PetscMalloc1(n,&ctx->vr);
 69: #if !defined(PETSC_USE_COMPLEX)
 70:   PetscMalloc1(n,&ctx->vi);
 71: #endif
 72:   for (i=0;i<n;i++) {
 73:     ctx->vr[i] = vr[i];
 74: #if !defined(PETSC_USE_COMPLEX)
 75:     ctx->vi[i] = vi[i];
 76: #endif
 77:   }
 78:   return(0);
 79: }

 81: /*@
 82:    RGPolygonSetVertices - Sets the vertices that define the polygon region.

 84:    Logically Collective on RG

 86:    Input Parameters:
 87: +  rg - the region context
 88: .  n  - number of vertices
 89: .  vr - array of vertices
 90: -  vi - array of vertices (imaginary part)

 92:    Options Database Keys:
 93: +  -rg_polygon_vertices - Sets the vertices
 94: -  -rg_polygon_verticesi - Sets the vertices (imaginary part)

 96:    Notes:
 97:    In the case of complex scalars, only argument vr is used, containing
 98:    the complex vertices; the list of vertices can be provided in the
 99:    command line with a comma-separated list of complex values
100:    [+/-][realnumber][+/-]realnumberi with no spaces.

102:    When PETSc is built with real scalars, the real and imaginary parts of
103:    the vertices must be provided in two separate arrays (or two lists in
104:    the command line). In this case, the region must be symmetric with
105:    respect to the real axis.

107:    Level: advanced

109: .seealso: RGPolygonGetVertices()
110: @*/
111: PetscErrorCode RGPolygonSetVertices(RG rg,PetscInt n,PetscScalar vr[],PetscScalar vi[])
112: {

119: #if !defined(PETSC_USE_COMPLEX)
121: #endif
122:   PetscTryMethod(rg,"RGPolygonSetVertices_C",(RG,PetscInt,PetscScalar*,PetscScalar*),(rg,n,vr,vi));
123:   return(0);
124: }

126: static PetscErrorCode RGPolygonGetVertices_Polygon(RG rg,PetscInt *n,PetscScalar **vr,PetscScalar **vi)
127: {
128:   RG_POLYGON *ctx = (RG_POLYGON*)rg->data;

131:   if (n)  *n  = ctx->n;
132:   if (vr) *vr = ctx->vr;
133:   if (vi) *vi = ctx->vi;
134:   return(0);
135: }

137: /*@
138:    RGPolygonGetVertices - Gets the vertices that define the polygon region.

140:    Not Collective

142:    Input Parameter:
143: .  rg     - the region context

145:    Output Parameters:
146: +  n  - number of vertices
147: .  vr - array of vertices
148: -  vi - array of vertices (imaginary part)

150:    Notes:
151:    The returned arrays must NOT be freed by the calling application.

153:    Level: advanced

155: .seealso: RGPolygonSetVertices()
156: @*/
157: PetscErrorCode RGPolygonGetVertices(RG rg,PetscInt *n,PetscScalar **vr,PetscScalar **vi)
158: {

163:   PetscUseMethod(rg,"RGPolygonGetVertices_C",(RG,PetscInt*,PetscScalar**,PetscScalar**),(rg,n,vr,vi));
164:   return(0);
165: }

167: PetscErrorCode RGView_Polygon(RG rg,PetscViewer viewer)
168: {
170:   RG_POLYGON     *ctx = (RG_POLYGON*)rg->data;
171:   PetscBool      isdraw,isascii;
172:   int            winw,winh;
173:   PetscDraw      draw;
174:   PetscDrawAxis  axis;
175:   PetscReal      a,b,c,d,ab,cd,lx,ly,w,x0,y0,x1,y1,scale=1.2;
176:   PetscInt       i;
177:   char           str[50];

180:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERDRAW,&isdraw);
181:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);
182:   if (isascii) {
183:     PetscViewerASCIIPrintf(viewer,"  vertices: ");
184:     PetscViewerASCIIUseTabs(viewer,PETSC_FALSE);
185:     for (i=0;i<ctx->n;i++) {
186: #if defined(PETSC_USE_COMPLEX)
187:       SlepcSNPrintfScalar(str,50,ctx->vr[i],PETSC_FALSE);
188: #else
189:       if (ctx->vi[i]!=0.0) {
190:         PetscSNPrintf(str,50,"%g%+gi",(double)ctx->vr[i],(double)ctx->vi[i]);
191:       } else {
192:         PetscSNPrintf(str,50,"%g",(double)ctx->vr[i]);
193:       }
194: #endif
195:       PetscViewerASCIIPrintf(viewer,"%s%s",str,(i<ctx->n-1)?", ":"");
196:     }
197:     PetscViewerASCIIPrintf(viewer,"\n");
198:     PetscViewerASCIIUseTabs(viewer,PETSC_TRUE);
199:   } else if (isdraw) {
200:     PetscViewerDrawGetDraw(viewer,0,&draw);
201:     PetscDrawCheckResizedWindow(draw);
202:     PetscDrawGetWindowSize(draw,&winw,&winh);
203:     winw = PetscMax(winw,1); winh = PetscMax(winh,1);
204:     PetscDrawClear(draw);
205:     PetscDrawSetTitle(draw,"Polygonal region");
206:     PetscDrawAxisCreate(draw,&axis);
207:     RGComputeBoundingBox_Polygon(rg,&a,&b,&c,&d);
208:     a *= rg->sfactor;
209:     b *= rg->sfactor;
210:     c *= rg->sfactor;
211:     d *= rg->sfactor;
212:     lx = b-a;
213:     ly = d-c;
214:     ab = (a+b)/2;
215:     cd = (c+d)/2;
216:     w  = scale*PetscMax(lx/winw,ly/winh)/2;
217:     PetscDrawAxisSetLimits(axis,ab-w*winw,ab+w*winw,cd-w*winh,cd+w*winh);
218:     PetscDrawAxisDraw(axis);
219:     PetscDrawAxisDestroy(&axis);
220:     for (i=0;i<ctx->n;i++) {
221: #if defined(PETSC_USE_COMPLEX)
222:       x0 = PetscRealPart(ctx->vr[i]); y0 = PetscImaginaryPart(ctx->vr[i]);
223:       if (i<ctx->n-1) {
224:         x1 = PetscRealPart(ctx->vr[i+1]); y1 = PetscImaginaryPart(ctx->vr[i+1]);
225:       } else {
226:         x1 = PetscRealPart(ctx->vr[0]); y1 = PetscImaginaryPart(ctx->vr[0]);
227:       }
228: #else
229:       x0 = ctx->vr[i]; y0 = ctx->vi[i];
230:       if (i<ctx->n-1) {
231:         x1 = ctx->vr[i+1]; y1 = ctx->vi[i+1];
232:       } else {
233:         x1 = ctx->vr[0]; y1 = ctx->vi[0];
234:       }
235: #endif
236:       PetscDrawLine(draw,x0*rg->sfactor,y0*rg->sfactor,x1*rg->sfactor,y1*rg->sfactor,PETSC_DRAW_MAGENTA);
237:     }
238:     PetscDrawFlush(draw);
239:     PetscDrawSave(draw);
240:     PetscDrawPause(draw);
241:   }
242:   return(0);
243: }

245: PetscErrorCode RGIsTrivial_Polygon(RG rg,PetscBool *trivial)
246: {
247:   RG_POLYGON *ctx = (RG_POLYGON*)rg->data;

250:   *trivial = PetscNot(ctx->n);
251:   return(0);
252: }

254: PetscErrorCode RGComputeContour_Polygon(RG rg,PetscInt n,PetscScalar *cr,PetscScalar *ci)
255: {
256:   RG_POLYGON  *ctx = (RG_POLYGON*)rg->data;
257:   PetscReal   length,h,d,rem=0.0;
258:   PetscInt    k=1,idx=ctx->n-1,i;
259:   PetscBool   ini=PETSC_FALSE;
260:   PetscScalar incr;
261: #if !defined(PETSC_USE_COMPLEX)
262:   PetscScalar inci;
263: #endif

266:   if (!ctx->n) SETERRQ(PetscObjectComm((PetscObject)rg),PETSC_ERR_ARG_WRONGSTATE,"No vertices have been set yet");
267:   length = SlepcAbsEigenvalue(ctx->vr[0]-ctx->vr[ctx->n-1],ctx->vi[0]-ctx->vi[ctx->n-1]);
268:   for (i=0;i<ctx->n-1;i++) length += SlepcAbsEigenvalue(ctx->vr[i]-ctx->vr[i+1],ctx->vi[i]-ctx->vi[i+1]);
269:   h = length/n;
270:   cr[0] = ctx->vr[0];
271: #if !defined(PETSC_USE_COMPLEX)
272:   ci[0] = ctx->vi[0];
273: #endif
274:   incr = ctx->vr[ctx->n-1]-ctx->vr[0];
275: #if !defined(PETSC_USE_COMPLEX)
276:   inci = ctx->vi[ctx->n-1]-ctx->vi[0];
277: #endif
278:   d = SlepcAbsEigenvalue(incr,inci);
279:   incr /= d;
280: #if !defined(PETSC_USE_COMPLEX)
281:   inci /= d;
282: #endif
283:   while (k<n) {
284:     if (ini) {
285:       incr = ctx->vr[idx]-ctx->vr[idx+1];
286: #if !defined(PETSC_USE_COMPLEX)
287:       inci = ctx->vi[idx]-ctx->vi[idx+1];
288: #endif
289:       d = SlepcAbsEigenvalue(incr,inci);
290:       incr /= d;
291: #if !defined(PETSC_USE_COMPLEX)
292:       inci /= d;
293: #endif
294:       if (rem+d>h) {
295:         cr[k] = ctx->vr[idx+1]+incr*(h-rem);
296: #if !defined(PETSC_USE_COMPLEX)
297:         ci[k] = ctx->vi[idx+1]+inci*(h-rem);
298: #endif
299:         k++;
300:         ini = PETSC_FALSE;
301:       } else {rem += d; idx--;}
302:     } else {
303: #if !defined(PETSC_USE_COMPLEX)
304:       rem = SlepcAbsEigenvalue(ctx->vr[idx]-cr[k-1],ctx->vi[idx]-ci[k-1]);
305: #else
306:       rem = PetscAbsScalar(ctx->vr[idx]-cr[k-1]);
307: #endif
308:       if (rem>h) {
309:         cr[k] = cr[k-1]+incr*h;
310: #if !defined(PETSC_USE_COMPLEX)
311:         ci[k] = ci[k-1]+inci*h;
312: #endif
313:         k++;
314:       } else {ini = PETSC_TRUE; idx--;}
315:     }
316:   }
317:   return(0);
318: }

320: PetscErrorCode RGComputeBoundingBox_Polygon(RG rg,PetscReal *a,PetscReal *b,PetscReal *c,PetscReal *d)
321: {
322:   RG_POLYGON *ctx = (RG_POLYGON*)rg->data;
323:   PetscInt   i;

326:   *a =  PETSC_MAX_REAL;
327:   *b = -PETSC_MAX_REAL;
328:   *c =  PETSC_MAX_REAL;
329:   *d = -PETSC_MAX_REAL;
330:   for (i=0;i<ctx->n;i++) {
331: #if defined(PETSC_USE_COMPLEX)
332:     if (a) *a = PetscMin(*a,PetscRealPart(ctx->vr[i]));
333:     if (b) *b = PetscMax(*b,PetscRealPart(ctx->vr[i]));
334:     if (c) *c = PetscMin(*c,PetscImaginaryPart(ctx->vr[i]));
335:     if (d) *d = PetscMax(*d,PetscImaginaryPart(ctx->vr[i]));
336: #else
337:     if (a) *a = PetscMin(*a,ctx->vr[i]);
338:     if (b) *b = PetscMax(*b,ctx->vr[i]);
339:     if (c) *c = PetscMin(*c,ctx->vi[i]);
340:     if (d) *d = PetscMax(*d,ctx->vi[i]);
341: #endif
342:   }
343:   return(0);
344: }

346: PetscErrorCode RGCheckInside_Polygon(RG rg,PetscReal px,PetscReal py,PetscInt *inout)
347: {
348:   RG_POLYGON *ctx = (RG_POLYGON*)rg->data;
349:   PetscReal  val,x[VERTMAX],y[VERTMAX];
350:   PetscBool  mx,my,nx,ny;
351:   PetscInt   i,j;

354:   for (i=0;i<ctx->n;i++) {
355: #if defined(PETSC_USE_COMPLEX)
356:     x[i] = PetscRealPart(ctx->vr[i])-px;
357:     y[i] = PetscImaginaryPart(ctx->vr[i])-py;
358: #else
359:     x[i] = ctx->vr[i]-px;
360:     y[i] = ctx->vi[i]-py;
361: #endif
362:   }
363:   *inout = -1;
364:   for (i=0;i<ctx->n;i++) {
365:     j = (i+1)%ctx->n;
366:     mx = PetscNot(x[i]<0.0);
367:     nx = PetscNot(x[j]<0.0);
368:     my = PetscNot(y[i]<0.0);
369:     ny = PetscNot(y[j]<0.0);
370:     if (!((my||ny) && (mx||nx)) || (mx&&nx)) continue;
371:     if (((my && ny && (mx||nx)) && (!(mx&&nx)))) {
372:       *inout = -*inout;
373:       continue;
374:     }
375:     val = (y[i]*x[j]-x[i]*y[j])/(x[j]-x[i]);
376:     if (PetscAbs(val)<10*PETSC_MACHINE_EPSILON) {
377:       *inout = 0;
378:       return(0);
379:     } else if (val>0.0) *inout = -*inout;
380:   }
381:   return(0);
382: }

384: PetscErrorCode RGSetFromOptions_Polygon(PetscOptionItems *PetscOptionsObject,RG rg)
385: {
387:   PetscScalar    array[VERTMAX];
388:   PetscInt       i,k;
389:   PetscBool      flg,flgi=PETSC_FALSE;
390: #if !defined(PETSC_USE_COMPLEX)
391:   PetscScalar    arrayi[VERTMAX];
392:   PetscInt       ki;
393: #else
394:   PetscScalar    *arrayi=NULL;
395: #endif

398:   PetscOptionsHead(PetscOptionsObject,"RG Polygon Options");

400:     k = VERTMAX;
401:     for (i=0;i<k;i++) array[i] = 0;
402:     PetscOptionsScalarArray("-rg_polygon_vertices","Vertices of polygon","RGPolygonSetVertices",array,&k,&flg);
403: #if !defined(PETSC_USE_COMPLEX)
404:     ki = VERTMAX;
405:     for (i=0;i<ki;i++) arrayi[i] = 0;
406:     PetscOptionsScalarArray("-rg_polygon_verticesi","Vertices of polygon (imaginary part)","RGPolygonSetVertices",arrayi,&ki,&flgi);
407:     if (ki!=k) SETERRQ2(PetscObjectComm((PetscObject)rg),PETSC_ERR_ARG_SIZ,"The number of real %D and imaginary %D parts do not match",k,ki);
408: #endif
409:     if (flg || flgi) { RGPolygonSetVertices(rg,k,array,arrayi); }

411:   PetscOptionsTail();
412:   return(0);
413: }

415: PetscErrorCode RGDestroy_Polygon(RG rg)
416: {
418:   RG_POLYGON     *ctx = (RG_POLYGON*)rg->data;

421:   if (ctx->n) {
422:     PetscFree(ctx->vr);
423: #if !defined(PETSC_USE_COMPLEX)
424:     PetscFree(ctx->vi);
425: #endif
426:   }
427:   PetscFree(rg->data);
428:   PetscObjectComposeFunction((PetscObject)rg,"RGPolygonSetVertices_C",NULL);
429:   PetscObjectComposeFunction((PetscObject)rg,"RGPolygonGetVertices_C",NULL);
430:   return(0);
431: }

433: SLEPC_EXTERN PetscErrorCode RGCreate_Polygon(RG rg)
434: {
435:   RG_POLYGON     *polygon;

439:   PetscNewLog(rg,&polygon);
440:   rg->data = (void*)polygon;

442:   rg->ops->istrivial      = RGIsTrivial_Polygon;
443:   rg->ops->computecontour = RGComputeContour_Polygon;
444:   rg->ops->computebbox    = RGComputeBoundingBox_Polygon;
445:   rg->ops->checkinside    = RGCheckInside_Polygon;
446:   rg->ops->setfromoptions = RGSetFromOptions_Polygon;
447:   rg->ops->view           = RGView_Polygon;
448:   rg->ops->destroy        = RGDestroy_Polygon;
449:   PetscObjectComposeFunction((PetscObject)rg,"RGPolygonSetVertices_C",RGPolygonSetVertices_Polygon);
450:   PetscObjectComposeFunction((PetscObject)rg,"RGPolygonGetVertices_C",RGPolygonGetVertices_Polygon);
451:   return(0);
452: }