Actual source code: rgpolygon.c
slepc-3.10.1 2018-10-23
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2018, 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: PETSC_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: }