Actual source code: lgc.c

  1: #include <petscviewer.h>
  2: #include <petsc/private/drawimpl.h>
  3: PetscClassId PETSC_DRAWLG_CLASSID = 0;

  5: /*@
  6:   PetscDrawLGGetAxis - Gets the axis context associated with a line graph.
  7:   This is useful if one wants to change some axis property, such as
  8:   labels, color, etc. The axis context should not be destroyed by the
  9:   application code.

 11:   Not Collective, if lg is parallel then axis is parallel

 13:   Input Parameter:
 14: . lg - the line graph context

 16:   Output Parameter:
 17: . axis - the axis context

 19:   Level: advanced

 21: .seealso: `PetscDrawLGCreate()`, `PetscDrawAxis`, `PetscDrawLG`
 22: @*/
 23: PetscErrorCode PetscDrawLGGetAxis(PetscDrawLG lg, PetscDrawAxis *axis)
 24: {
 25:   PetscFunctionBegin;
 27:   PetscAssertPointer(axis, 2);
 28:   *axis = lg->axis;
 29:   PetscFunctionReturn(PETSC_SUCCESS);
 30: }

 32: /*@
 33:   PetscDrawLGGetDraw - Gets the draw context associated with a line graph.

 35:   Not Collective, if lg is parallel then draw is parallel

 37:   Input Parameter:
 38: . lg - the line graph context

 40:   Output Parameter:
 41: . draw - the draw context

 43:   Level: intermediate

 45: .seealso: `PetscDrawLGCreate()`, `PetscDraw`, `PetscDrawLG`
 46: @*/
 47: PetscErrorCode PetscDrawLGGetDraw(PetscDrawLG lg, PetscDraw *draw)
 48: {
 49:   PetscFunctionBegin;
 51:   PetscAssertPointer(draw, 2);
 52:   *draw = lg->win;
 53:   PetscFunctionReturn(PETSC_SUCCESS);
 54: }

 56: /*@
 57:   PetscDrawLGSPDraw - Redraws a line graph and a scatter plot on the same `PetscDraw` they must share

 59:   Collective

 61:   Input Parameters:
 62: + lg   - the line graph context
 63: - spin - the scatter plot

 65:   Level: intermediate

 67:   Developer Notes:
 68:   This code cheats and uses the fact that the `PetscDrawLG` and `PetscDrawSP` structs are the same

 70: .seealso: `PetscDrawLGDraw()`, `PetscDrawSPDraw()`
 71: @*/
 72: PetscErrorCode PetscDrawLGSPDraw(PetscDrawLG lg, PetscDrawSP spin)
 73: {
 74:   PetscDrawLG sp = (PetscDrawLG)spin;
 75:   PetscReal   xmin, xmax, ymin, ymax;
 76:   PetscBool   isnull;
 77:   PetscMPIInt rank;
 78:   PetscDraw   draw;

 80:   PetscFunctionBegin;
 83:   PetscCall(PetscDrawIsNull(lg->win, &isnull));
 84:   if (isnull) PetscFunctionReturn(PETSC_SUCCESS);
 85:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)lg), &rank));

 87:   draw = lg->win;
 88:   PetscCall(PetscDrawCheckResizedWindow(draw));
 89:   PetscCall(PetscDrawClear(draw));

 91:   xmin = PetscMin(lg->xmin, sp->xmin);
 92:   ymin = PetscMin(lg->ymin, sp->ymin);
 93:   xmax = PetscMax(lg->xmax, sp->xmax);
 94:   ymax = PetscMax(lg->ymax, sp->ymax);
 95:   PetscCall(PetscDrawAxisSetLimits(lg->axis, xmin, xmax, ymin, ymax));
 96:   PetscCall(PetscDrawAxisDraw(lg->axis));

 98:   PetscDrawCollectiveBegin(draw);
 99:   if (rank == 0) {
100:     int i, j, dim, nopts;
101:     dim   = lg->dim;
102:     nopts = lg->nopts;
103:     for (i = 0; i < dim; i++) {
104:       for (j = 1; j < nopts; j++) {
105:         PetscCall(PetscDrawLine(draw, lg->x[(j - 1) * dim + i], lg->y[(j - 1) * dim + i], lg->x[j * dim + i], lg->y[j * dim + i], PETSC_DRAW_BLACK + i));
106:         if (lg->use_markers) PetscCall(PetscDrawMarker(draw, lg->x[j * dim + i], lg->y[j * dim + i], PETSC_DRAW_RED));
107:       }
108:     }
109:     dim   = sp->dim;
110:     nopts = sp->nopts;
111:     for (i = 0; i < dim; i++) {
112:       for (j = 0; j < nopts; j++) PetscCall(PetscDrawMarker(draw, sp->x[j * dim + i], sp->y[j * dim + i], PETSC_DRAW_RED));
113:     }
114:   }
115:   PetscDrawCollectiveEnd(draw);

117:   PetscCall(PetscDrawFlush(draw));
118:   PetscCall(PetscDrawPause(draw));
119:   PetscFunctionReturn(PETSC_SUCCESS);
120: }

122: /*@
123:   PetscDrawLGCreate - Creates a line graph data structure.

125:   Collective

127:   Input Parameters:
128: + draw - the window where the graph will be made.
129: - dim  - the number of curves which will be drawn

131:   Output Parameter:
132: . outlg - the line graph context

134:   Level: intermediate

136:   Notes:
137:   The MPI communicator that owns the `PetscDraw` owns this `PetscDrawLG`, but the calls to set options and add points are ignored on all processes except the
138:   zeroth MPI process in the communicator.

140:   All MPI ranks in the communicator must call `PetscDrawLGDraw()` to display the updated graph.

142: .seealso: `PetscDrawLGDestroy()`, `PetscDrawLGAddPoint()`, `PetscDrawLGAddCommonPoint()`, `PetscDrawLGAddPoints()`, `PetscDrawLGDraw()`, `PetscDrawLGSave()`,
143:           `PetscDrawLGView()`, `PetscDrawLGReset()`, `PetscDrawLGSetDimension()`, `PetscDrawLGGetDimension()`, `PetscDrawLGSetLegend()`, `PetscDrawLGGetAxis()`,
144:           `PetscDrawLGGetDraw()`, `PetscDrawLGSetUseMarkers()`, `PetscDrawLGSetLimits()`, `PetscDrawLGSetColors()`, `PetscDrawLGSetOptionsPrefix()`, `PetscDrawLGSetFromOptions()`
145: @*/
146: PetscErrorCode PetscDrawLGCreate(PetscDraw draw, PetscInt dim, PetscDrawLG *outlg)
147: {
148:   PetscDrawLG lg;

150:   PetscFunctionBegin;
153:   PetscAssertPointer(outlg, 3);

155:   PetscCall(PetscHeaderCreate(lg, PETSC_DRAWLG_CLASSID, "DrawLG", "Line Graph", "Draw", PetscObjectComm((PetscObject)draw), PetscDrawLGDestroy, NULL));
156:   PetscCall(PetscDrawLGSetOptionsPrefix(lg, ((PetscObject)draw)->prefix));

158:   PetscCall(PetscObjectReference((PetscObject)draw));
159:   lg->win = draw;

161:   lg->view    = NULL;
162:   lg->destroy = NULL;
163:   lg->nopts   = 0;
164:   lg->xmin    = 1.e20;
165:   lg->ymin    = 1.e20;
166:   lg->xmax    = -1.e20;
167:   lg->ymax    = -1.e20;
168:   PetscCall(PetscCIntCast(dim, &lg->dim));
169:   PetscCall(PetscMalloc2(dim * PETSC_DRAW_LG_CHUNK_SIZE, &lg->x, dim * PETSC_DRAW_LG_CHUNK_SIZE, &lg->y));

171:   lg->len         = lg->dim * PETSC_DRAW_LG_CHUNK_SIZE;
172:   lg->loc         = 0;
173:   lg->use_markers = PETSC_FALSE;

175:   PetscCall(PetscDrawAxisCreate(draw, &lg->axis));

177:   *outlg = lg;
178:   PetscFunctionReturn(PETSC_SUCCESS);
179: }

181: /*@
182:   PetscDrawLGSetColors - Sets the color of each line graph drawn

184:   Logically Collective

186:   Input Parameters:
187: + lg     - the line graph context.
188: - colors - the colors

190:   Level: intermediate

192: .seealso: `PetscDrawLG`, `PetscDrawLGCreate()`
193: @*/
194: PetscErrorCode PetscDrawLGSetColors(PetscDrawLG lg, const int colors[])
195: {
196:   PetscFunctionBegin;
198:   if (lg->dim) PetscAssertPointer(colors, 2);

200:   PetscCall(PetscFree(lg->colors));
201:   PetscCall(PetscMalloc1(lg->dim, &lg->colors));
202:   PetscCall(PetscArraycpy(lg->colors, colors, lg->dim));
203:   PetscFunctionReturn(PETSC_SUCCESS);
204: }

206: /*@C
207:   PetscDrawLGSetLegend - sets the names of each curve plotted

209:   Logically Collective

211:   Input Parameters:
212: + lg    - the line graph context.
213: - names - the names for each curve

215:   Level: intermediate

217:   Note:
218:   Call `PetscDrawLGGetAxis()` and then change properties of the `PetscDrawAxis` for detailed control of the plot

220: .seealso: `PetscDrawLGGetAxis()`, `PetscDrawAxis`, `PetscDrawAxisSetColors()`, `PetscDrawAxisSetLabels()`, `PetscDrawAxisSetHoldLimits()`
221: @*/
222: PetscErrorCode PetscDrawLGSetLegend(PetscDrawLG lg, const char *const names[])
223: {
224:   PetscInt i;

226:   PetscFunctionBegin;
228:   if (names) PetscAssertPointer(names, 2);

230:   if (lg->legend) {
231:     for (i = 0; i < lg->dim; i++) PetscCall(PetscFree(lg->legend[i]));
232:     PetscCall(PetscFree(lg->legend));
233:   }
234:   if (names) {
235:     PetscCall(PetscMalloc1(lg->dim, &lg->legend));
236:     for (i = 0; i < lg->dim; i++) PetscCall(PetscStrallocpy(names[i], &lg->legend[i]));
237:   }
238:   PetscFunctionReturn(PETSC_SUCCESS);
239: }

241: /*@
242:   PetscDrawLGGetDimension - Get the number of curves that are to be drawn.

244:   Not Collective

246:   Input Parameter:
247: . lg - the line graph context.

249:   Output Parameter:
250: . dim - the number of curves.

252:   Level: intermediate

254: .seealso: `PetscDrawLGC`, `PetscDrawLGCreate()`, `PetscDrawLGSetDimension()`
255: @*/
256: PetscErrorCode PetscDrawLGGetDimension(PetscDrawLG lg, PetscInt *dim)
257: {
258:   PetscFunctionBegin;
260:   PetscAssertPointer(dim, 2);
261:   *dim = lg->dim;
262:   PetscFunctionReturn(PETSC_SUCCESS);
263: }

265: /*@
266:   PetscDrawLGSetDimension - Change the number of curves that are to be drawn.

268:   Logically Collective

270:   Input Parameters:
271: + lg  - the line graph context.
272: - dim - the number of curves.

274:   Level: intermediate

276: .seealso: `PetscDrawLGCreate()`, `PetscDrawLGGetDimension()`
277: @*/
278: PetscErrorCode PetscDrawLGSetDimension(PetscDrawLG lg, PetscInt dim)
279: {
280:   PetscInt i;

282:   PetscFunctionBegin;
285:   if (lg->dim == dim) PetscFunctionReturn(PETSC_SUCCESS);

287:   PetscCall(PetscFree2(lg->x, lg->y));
288:   if (lg->legend) {
289:     for (i = 0; i < lg->dim; i++) PetscCall(PetscFree(lg->legend[i]));
290:     PetscCall(PetscFree(lg->legend));
291:   }
292:   PetscCall(PetscFree(lg->colors));
293:   PetscCall(PetscCIntCast(dim, &lg->dim));
294:   PetscCall(PetscMalloc2(dim * PETSC_DRAW_LG_CHUNK_SIZE, &lg->x, dim * PETSC_DRAW_LG_CHUNK_SIZE, &lg->y));
295:   lg->len = lg->dim * PETSC_DRAW_LG_CHUNK_SIZE;
296:   PetscFunctionReturn(PETSC_SUCCESS);
297: }

299: /*@
300:   PetscDrawLGSetLimits - Sets the axis limits for a line graph. If more
301:   points are added after this call, the limits will be adjusted to
302:   include those additional points.

304:   Logically Collective

306:   Input Parameters:
307: + lg    - the line graph context
308: . x_min - the horizontal lower limit
309: . x_max - the horizontal upper limit
310: . y_min - the vertical lower limit
311: - y_max - the vertical upper limit

313:   Level: intermediate

315: .seealso: `PetscDrawLGCreate()`, `PetscDrawLG`, `PetscDrawAxis`
316: @*/
317: PetscErrorCode PetscDrawLGSetLimits(PetscDrawLG lg, PetscReal x_min, PetscReal x_max, PetscReal y_min, PetscReal y_max)
318: {
319:   PetscFunctionBegin;

322:   (lg)->xmin = x_min;
323:   (lg)->xmax = x_max;
324:   (lg)->ymin = y_min;
325:   (lg)->ymax = y_max;
326:   PetscFunctionReturn(PETSC_SUCCESS);
327: }

329: /*@
330:   PetscDrawLGReset - Clears line graph to allow for reuse with new data.

332:   Logically Collective

334:   Input Parameter:
335: . lg - the line graph context.

337:   Level: intermediate

339: .seealso: `PetscDrawLG`, `PetscDrawLGCreate()`
340: @*/
341: PetscErrorCode PetscDrawLGReset(PetscDrawLG lg)
342: {
343:   PetscFunctionBegin;
345:   lg->xmin  = 1.e20;
346:   lg->ymin  = 1.e20;
347:   lg->xmax  = -1.e20;
348:   lg->ymax  = -1.e20;
349:   lg->loc   = 0;
350:   lg->nopts = 0;
351:   PetscFunctionReturn(PETSC_SUCCESS);
352: }

354: /*@
355:   PetscDrawLGDestroy - Frees all space taken up by line graph data structure.

357:   Collective

359:   Input Parameter:
360: . lg - the line graph context

362:   Level: intermediate

364: .seealso: `PetscDrawLG`, `PetscDrawLGCreate()`
365: @*/
366: PetscErrorCode PetscDrawLGDestroy(PetscDrawLG *lg)
367: {
368:   PetscInt i;

370:   PetscFunctionBegin;
371:   if (!*lg) PetscFunctionReturn(PETSC_SUCCESS);
373:   if (--((PetscObject)*lg)->refct > 0) {
374:     *lg = NULL;
375:     PetscFunctionReturn(PETSC_SUCCESS);
376:   }

378:   if ((*lg)->legend) {
379:     for (i = 0; i < (*lg)->dim; i++) PetscCall(PetscFree((*lg)->legend[i]));
380:     PetscCall(PetscFree((*lg)->legend));
381:   }
382:   PetscCall(PetscFree((*lg)->colors));
383:   PetscCall(PetscFree2((*lg)->x, (*lg)->y));
384:   PetscCall(PetscDrawAxisDestroy(&(*lg)->axis));
385:   PetscCall(PetscDrawDestroy(&(*lg)->win));
386:   PetscCall(PetscHeaderDestroy(lg));
387:   PetscFunctionReturn(PETSC_SUCCESS);
388: }
389: /*@
390:   PetscDrawLGSetUseMarkers - Causes the line graph object to draw a marker for each data-point.

392:   Logically Collective

394:   Input Parameters:
395: + lg  - the linegraph context
396: - flg - should mark each data point

398:   Options Database Key:
399: . -lg_use_markers  <true,false> - true means it draws a marker for each point

401:   Level: intermediate

403: .seealso: `PetscDrawLG`, `PetscDrawLGCreate()`
404: @*/
405: PetscErrorCode PetscDrawLGSetUseMarkers(PetscDrawLG lg, PetscBool flg)
406: {
407:   PetscFunctionBegin;
410:   lg->use_markers = flg;
411:   PetscFunctionReturn(PETSC_SUCCESS);
412: }

414: /*@
415:   PetscDrawLGDraw - Redraws a line graph.

417:   Collective

419:   Input Parameter:
420: . lg - the line graph context

422:   Level: intermediate

424: .seealso: `PetscDrawLG`, `PetscDrawSPDraw()`, `PetscDrawLGSPDraw()`, `PetscDrawLGReset()`
425: @*/
426: PetscErrorCode PetscDrawLGDraw(PetscDrawLG lg)
427: {
428:   PetscReal   xmin, xmax, ymin, ymax;
429:   PetscMPIInt rank;
430:   PetscDraw   draw;
431:   PetscBool   isnull;

433:   PetscFunctionBegin;
435:   PetscCall(PetscDrawIsNull(lg->win, &isnull));
436:   if (isnull) PetscFunctionReturn(PETSC_SUCCESS);
437:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)lg), &rank));

439:   draw = lg->win;
440:   PetscCall(PetscDrawCheckResizedWindow(draw));
441:   PetscCall(PetscDrawClear(draw));

443:   xmin = lg->xmin;
444:   xmax = lg->xmax;
445:   ymin = lg->ymin;
446:   ymax = lg->ymax;
447:   PetscCall(PetscDrawAxisSetLimits(lg->axis, xmin, xmax, ymin, ymax));
448:   PetscCall(PetscDrawAxisDraw(lg->axis));

450:   PetscDrawCollectiveBegin(draw);
451:   if (rank == 0) {
452:     int i, j, dim = lg->dim, nopts = lg->nopts, cl;
453:     for (i = 0; i < dim; i++) {
454:       for (j = 1; j < nopts; j++) {
455:         cl = lg->colors ? lg->colors[i] : ((PETSC_DRAW_BLACK + i) % PETSC_DRAW_MAXCOLOR);
456:         PetscCall(PetscDrawLine(draw, lg->x[(j - 1) * dim + i], lg->y[(j - 1) * dim + i], lg->x[j * dim + i], lg->y[j * dim + i], cl));
457:         if (lg->use_markers) PetscCall(PetscDrawMarker(draw, lg->x[j * dim + i], lg->y[j * dim + i], cl));
458:       }
459:     }
460:   }
461:   if (rank == 0 && lg->legend) {
462:     PetscBool right = PETSC_FALSE;
463:     int       i, dim = lg->dim, cl;
464:     PetscReal xl, yl, xr, yr, tw, th;
465:     size_t    slen, len = 0;

467:     PetscCall(PetscDrawAxisGetLimits(lg->axis, &xl, &xr, &yl, &yr));
468:     PetscCall(PetscDrawStringGetSize(draw, &tw, &th));
469:     for (i = 0; i < dim; i++) {
470:       PetscCall(PetscStrlen(lg->legend[i], &slen));
471:       len = PetscMax(len, slen);
472:     }
473:     if (right) {
474:       xr = xr - 1.5 * tw;
475:       xl = xr - ((PetscReal)len + 7) * tw;
476:     } else {
477:       xl = xl + 1.5 * tw;
478:       xr = xl + ((PetscReal)len + 7) * tw;
479:     }
480:     yr = yr - 1.0 * th;
481:     yl = yr - (dim + 1) * th;
482:     PetscCall(PetscDrawLine(draw, xl, yl, xr, yl, PETSC_DRAW_BLACK));
483:     PetscCall(PetscDrawLine(draw, xr, yl, xr, yr, PETSC_DRAW_BLACK));
484:     PetscCall(PetscDrawLine(draw, xr, yr, xl, yr, PETSC_DRAW_BLACK));
485:     PetscCall(PetscDrawLine(draw, xl, yr, xl, yl, PETSC_DRAW_BLACK));
486:     for (i = 0; i < dim; i++) {
487:       cl = lg->colors ? lg->colors[i] : (PETSC_DRAW_BLACK + i);
488:       PetscCall(PetscDrawLine(draw, xl + 1 * tw, yr - (i + 1) * th, xl + 5 * tw, yr - (i + 1) * th, cl));
489:       PetscCall(PetscDrawString(draw, xl + 6 * tw, yr - (i + 1.5) * th, PETSC_DRAW_BLACK, lg->legend[i]));
490:     }
491:   }
492:   PetscDrawCollectiveEnd(draw);

494:   PetscCall(PetscDrawFlush(draw));
495:   PetscCall(PetscDrawPause(draw));
496:   PetscFunctionReturn(PETSC_SUCCESS);
497: }

499: /*@
500:   PetscDrawLGSave - Saves a drawn image

502:   Collective

504:   Input Parameter:
505: . lg - The line graph context

507:   Level: intermediate

509: .seealso: `PetscDrawLG`, `PetscDrawSave()`, `PetscDrawLGCreate()`, `PetscDrawLGGetDraw()`, `PetscDrawSetSave()`
510: @*/
511: PetscErrorCode PetscDrawLGSave(PetscDrawLG lg)
512: {
513:   PetscFunctionBegin;
515:   PetscCall(PetscDrawSave(lg->win));
516:   PetscFunctionReturn(PETSC_SUCCESS);
517: }

519: /*@
520:   PetscDrawLGView - Prints a line graph.

522:   Collective

524:   Input Parameters:
525: + lg     - the line graph context
526: - viewer - the viewer to view it with

528:   Level: beginner

530: .seealso: `PetscDrawLG`, `PetscDrawLGCreate()`
531: @*/
532: PetscErrorCode PetscDrawLGView(PetscDrawLG lg, PetscViewer viewer)
533: {
534:   PetscReal xmin = lg->xmin, xmax = lg->xmax, ymin = lg->ymin, ymax = lg->ymax;
535:   PetscInt  i, j, dim = lg->dim, nopts = lg->nopts;

537:   PetscFunctionBegin;

540:   if (nopts < 1) PetscFunctionReturn(PETSC_SUCCESS);
541:   if (xmin > xmax || ymin > ymax) PetscFunctionReturn(PETSC_SUCCESS);

543:   if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)lg), &viewer));
544:   PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)lg, viewer));
545:   for (i = 0; i < dim; i++) {
546:     PetscCall(PetscViewerASCIIPrintf(viewer, "Line %" PetscInt_FMT ">\n", i));
547:     for (j = 0; j < nopts; j++) PetscCall(PetscViewerASCIIPrintf(viewer, "  X: %g Y: %g\n", (double)lg->x[j * dim + i], (double)lg->y[j * dim + i]));
548:   }
549:   PetscFunctionReturn(PETSC_SUCCESS);
550: }

552: /*@
553:   PetscDrawLGSetOptionsPrefix - Sets the prefix used for searching for all
554:   `PetscDrawLG` options in the database.

556:   Logically Collective

558:   Input Parameters:
559: + lg     - the line graph context
560: - prefix - the prefix to prepend to all option names

562:   Level: advanced

564: .seealso: `PetscDrawLG`, `PetscDrawLGSetFromOptions()`, `PetscDrawLGCreate()`
565: @*/
566: PetscErrorCode PetscDrawLGSetOptionsPrefix(PetscDrawLG lg, const char prefix[])
567: {
568:   PetscFunctionBegin;
570:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)lg, prefix));
571:   PetscFunctionReturn(PETSC_SUCCESS);
572: }

574: /*@
575:   PetscDrawLGSetFromOptions - Sets options related to the line graph object

577:   Collective

579:   Input Parameters:
580: . lg - the line graph context

582:   Options Database Key:
583: . -lg_use_markers  <true,false> - true means it draws a marker for each point

585:   Level: intermediate

587: .seealso: `PetscDrawLG`, `PetscDrawLGDestroy()`, `PetscDrawLGCreate()`
588: @*/
589: PetscErrorCode PetscDrawLGSetFromOptions(PetscDrawLG lg)
590: {
591:   PetscBool           usemarkers, set;
592:   PetscDrawMarkerType markertype;

594:   PetscFunctionBegin;

597:   PetscCall(PetscDrawGetMarkerType(lg->win, &markertype));
598:   PetscCall(PetscOptionsGetEnum(((PetscObject)lg)->options, ((PetscObject)lg)->prefix, "-lg_marker_type", PetscDrawMarkerTypes, (PetscEnum *)&markertype, &set));
599:   if (set) {
600:     PetscCall(PetscDrawLGSetUseMarkers(lg, PETSC_TRUE));
601:     PetscCall(PetscDrawSetMarkerType(lg->win, markertype));
602:   }
603:   usemarkers = lg->use_markers;
604:   PetscCall(PetscOptionsGetBool(((PetscObject)lg)->options, ((PetscObject)lg)->prefix, "-lg_use_markers", &usemarkers, &set));
605:   if (set) PetscCall(PetscDrawLGSetUseMarkers(lg, usemarkers));
606:   PetscFunctionReturn(PETSC_SUCCESS);
607: }