Date: 2026-03-31T05:46:28+00:00

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, an array of length the value set with `PetscDrawLGSetDimension()`

    190:   Level: intermediate

    192: .seealso: `PetscDrawLG`, `PetscDrawLGCreate()`, `PetscDrawLGSetDimension()`, `PetscDrawLGGetDimension()`
    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: /*@C
    300:   PetscDrawLGGetData - Get the data being plotted.

    302:   Not Collective

    304:   Input Parameter:
    305: . lg - the line graph context

    307:   Output Parameters:
    308: + dim - the number of curves
    309: . n   - the number of points on each line
    310: . x   - The x-value of each point, x[p * dim + c]
    311: - y   - The y-value of each point, y[p * dim + c]

    313:   Level: intermediate

    315: .seealso: `PetscDrawLGC`, `PetscDrawLGCreate()`, `PetscDrawLGGetDimension()`
    316: @*/
    317: PetscErrorCode PetscDrawLGGetData(PetscDrawLG lg, PetscInt *dim, PetscInt *n, const PetscReal *x[], const PetscReal *y[])
    318: {
    319:   PetscFunctionBegin;
    321:   if (dim) {
    322:     PetscAssertPointer(dim, 2);
    323:     *dim = lg->dim;
    324:   }
    325:   if (n) {
    326:     PetscAssertPointer(n, 3);
    327:     *n = lg->nopts;
    328:   }
    329:   if (x) {
    330:     PetscAssertPointer(x, 4);
    331:     *x = lg->x;
    332:   }
    333:   if (y) {
    334:     PetscAssertPointer(y, 5);
    335:     *y = lg->y;
    336:   }
    337:   PetscFunctionReturn(PETSC_SUCCESS);
    338: }

    340: /*@
    341:   PetscDrawLGSetLimits - Sets the axis limits for a line graph. If more
    342:   points are added after this call, the limits will be adjusted to
    343:   include those additional points.

    345:   Logically Collective

    347:   Input Parameters:
    348: + lg    - the line graph context
    349: . x_min - the horizontal lower limit
    350: . x_max - the horizontal upper limit
    351: . y_min - the vertical lower limit
    352: - y_max - the vertical upper limit

    354:   Level: intermediate

    356: .seealso: `PetscDrawLGCreate()`, `PetscDrawLG`, `PetscDrawAxis`
    357: @*/
    358: PetscErrorCode PetscDrawLGSetLimits(PetscDrawLG lg, PetscReal x_min, PetscReal x_max, PetscReal y_min, PetscReal y_max)
    359: {
    360:   PetscFunctionBegin;

    363:   (lg)->xmin = x_min;
    364:   (lg)->xmax = x_max;
    365:   (lg)->ymin = y_min;
    366:   (lg)->ymax = y_max;
    367:   PetscFunctionReturn(PETSC_SUCCESS);
    368: }

    370: /*@
    371:   PetscDrawLGReset - Clears line graph to allow for reuse with new data.

    373:   Logically Collective

    375:   Input Parameter:
    376: . lg - the line graph context.

    378:   Level: intermediate

    380: .seealso: `PetscDrawLG`, `PetscDrawLGCreate()`
    381: @*/
    382: PetscErrorCode PetscDrawLGReset(PetscDrawLG lg)
    383: {
    384:   PetscFunctionBegin;
    386:   lg->xmin  = 1.e20;
    387:   lg->ymin  = 1.e20;
    388:   lg->xmax  = -1.e20;
    389:   lg->ymax  = -1.e20;
    390:   lg->loc   = 0;
    391:   lg->nopts = 0;
    392:   PetscFunctionReturn(PETSC_SUCCESS);
    393: }

    395: /*@
    396:   PetscDrawLGDestroy - Frees all space taken up by line graph data structure.

    398:   Collective

    400:   Input Parameter:
    401: . lg - the line graph context

    403:   Level: intermediate

    405: .seealso: `PetscDrawLG`, `PetscDrawLGCreate()`
    406: @*/
    407: PetscErrorCode PetscDrawLGDestroy(PetscDrawLG *lg)
    408: {
    409:   PetscInt i;

    411:   PetscFunctionBegin;
    412:   if (!*lg) PetscFunctionReturn(PETSC_SUCCESS);
    414:   if (--((PetscObject)*lg)->refct > 0) {
    415:     *lg = NULL;
    416:     PetscFunctionReturn(PETSC_SUCCESS);
    417:   }

    419:   if ((*lg)->legend) {
    420:     for (i = 0; i < (*lg)->dim; i++) PetscCall(PetscFree((*lg)->legend[i]));
    421:     PetscCall(PetscFree((*lg)->legend));
    422:   }
    423:   PetscCall(PetscFree((*lg)->colors));
    424:   PetscCall(PetscFree2((*lg)->x, (*lg)->y));
    425:   PetscCall(PetscDrawAxisDestroy(&(*lg)->axis));
    426:   PetscCall(PetscDrawDestroy(&(*lg)->win));
    427:   PetscCall(PetscHeaderDestroy(lg));
    428:   PetscFunctionReturn(PETSC_SUCCESS);
    429: }
    430: /*@
    431:   PetscDrawLGSetUseMarkers - Causes the line graph object to draw a marker for each data-point.

    433:   Logically Collective

    435:   Input Parameters:
    436: + lg  - the linegraph context
    437: - flg - should mark each data point

    439:   Options Database Key:
    440: . -lg_use_markers (true|false) - true means it draws a marker for each point

    442:   Level: intermediate

    444: .seealso: `PetscDrawLG`, `PetscDrawLGCreate()`
    445: @*/
    446: PetscErrorCode PetscDrawLGSetUseMarkers(PetscDrawLG lg, PetscBool flg)
    447: {
    448:   PetscFunctionBegin;
    451:   lg->use_markers = flg;
    452:   PetscFunctionReturn(PETSC_SUCCESS);
    453: }

    455: /*@
    456:   PetscDrawLGDraw - Redraws a line graph.

    458:   Collective

    460:   Input Parameter:
    461: . lg - the line graph context

    463:   Level: intermediate

    465: .seealso: `PetscDrawLG`, `PetscDrawSPDraw()`, `PetscDrawLGSPDraw()`, `PetscDrawLGReset()`
    466: @*/
    467: PetscErrorCode PetscDrawLGDraw(PetscDrawLG lg)
    468: {
    469:   PetscReal   xmin, xmax, ymin, ymax;
    470:   PetscMPIInt rank;
    471:   PetscDraw   draw;
    472:   PetscBool   isnull;

    474:   PetscFunctionBegin;
    476:   PetscCall(PetscDrawIsNull(lg->win, &isnull));
    477:   if (isnull) PetscFunctionReturn(PETSC_SUCCESS);
    478:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)lg), &rank));

    480:   draw = lg->win;
    481:   PetscCall(PetscDrawCheckResizedWindow(draw));
    482:   PetscCall(PetscDrawClear(draw));

    484:   xmin = lg->xmin;
    485:   xmax = lg->xmax;
    486:   ymin = lg->ymin;
    487:   ymax = lg->ymax;
    488:   // Try not to freak out the axis
    489:   if (ymax - ymin < PETSC_SMALL) {
    490:     ymin -= 0.1 * ymax;
    491:     ymax += 0.1 * ymax;
    492:   }
    493:   PetscCall(PetscDrawAxisSetLimits(lg->axis, xmin, xmax, ymin, ymax));
    494:   PetscCall(PetscDrawAxisDraw(lg->axis));

    496:   PetscDrawCollectiveBegin(draw);
    497:   if (rank == 0) {
    498:     int i, j, dim = lg->dim, nopts = lg->nopts, cl;
    499:     for (i = 0; i < dim; i++) {
    500:       for (j = 1; j < nopts; j++) {
    501:         cl = lg->colors ? lg->colors[i] : ((PETSC_DRAW_BLACK + i) % PETSC_DRAW_MAXCOLOR);
    502:         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));
    503:         if (lg->use_markers) PetscCall(PetscDrawMarker(draw, lg->x[j * dim + i], lg->y[j * dim + i], cl));
    504:       }
    505:     }
    506:   }
    507:   if (rank == 0 && lg->legend) {
    508:     PetscBool right = PETSC_FALSE;
    509:     int       i, dim = lg->dim, cl;
    510:     PetscReal xl, yl, xr, yr, tw, th;
    511:     size_t    slen, len = 0;

    513:     PetscCall(PetscDrawAxisGetLimits(lg->axis, &xl, &xr, &yl, &yr));
    514:     PetscCall(PetscDrawStringGetSize(draw, &tw, &th));
    515:     for (i = 0; i < dim; i++) {
    516:       PetscCall(PetscStrlen(lg->legend[i], &slen));
    517:       len = PetscMax(len, slen);
    518:     }
    519:     if (right) {
    520:       xr = xr - 1.5 * tw;
    521:       xl = xr - ((PetscReal)len + 7) * tw;
    522:     } else {
    523:       xl = xl + 1.5 * tw;
    524:       xr = xl + ((PetscReal)len + 7) * tw;
    525:     }
    526:     yr = yr - 1.0 * th;
    527:     yl = yr - (dim + 1) * th;
    528:     PetscCall(PetscDrawLine(draw, xl, yl, xr, yl, PETSC_DRAW_BLACK));
    529:     PetscCall(PetscDrawLine(draw, xr, yl, xr, yr, PETSC_DRAW_BLACK));
    530:     PetscCall(PetscDrawLine(draw, xr, yr, xl, yr, PETSC_DRAW_BLACK));
    531:     PetscCall(PetscDrawLine(draw, xl, yr, xl, yl, PETSC_DRAW_BLACK));
    532:     for (i = 0; i < dim; i++) {
    533:       cl = lg->colors ? lg->colors[i] : (PETSC_DRAW_BLACK + i);
    534:       PetscCall(PetscDrawLine(draw, xl + 1 * tw, yr - (i + 1) * th, xl + 5 * tw, yr - (i + 1) * th, cl));
    535:       PetscCall(PetscDrawString(draw, xl + 6 * tw, yr - (i + 1.5) * th, PETSC_DRAW_BLACK, lg->legend[i]));
    536:     }
    537:   }
    538:   PetscDrawCollectiveEnd(draw);

    540:   PetscCall(PetscDrawFlush(draw));
    541:   PetscCall(PetscDrawPause(draw));
    542:   PetscFunctionReturn(PETSC_SUCCESS);
    543: }

    545: /*@
    546:   PetscDrawLGSave - Saves a drawn image

    548:   Collective

    550:   Input Parameter:
    551: . lg - The line graph context

    553:   Level: intermediate

    555: .seealso: `PetscDrawLG`, `PetscDrawSave()`, `PetscDrawLGCreate()`, `PetscDrawLGGetDraw()`, `PetscDrawSetSave()`
    556: @*/
    557: PetscErrorCode PetscDrawLGSave(PetscDrawLG lg)
    558: {
    559:   PetscFunctionBegin;
    561:   PetscCall(PetscDrawSave(lg->win));
    562:   PetscFunctionReturn(PETSC_SUCCESS);
    563: }

    565: /*@
    566:   PetscDrawLGView - Prints a line graph.

    568:   Collective

    570:   Input Parameters:
    571: + lg     - the line graph context
    572: - viewer - the viewer to view it with

    574:   Level: beginner

    576: .seealso: `PetscDrawLG`, `PetscDrawLGCreate()`
    577: @*/
    578: PetscErrorCode PetscDrawLGView(PetscDrawLG lg, PetscViewer viewer)
    579: {
    580:   PetscReal xmin = lg->xmin, xmax = lg->xmax, ymin = lg->ymin, ymax = lg->ymax;
    581:   PetscInt  i, j, dim = lg->dim, nopts = lg->nopts;

    583:   PetscFunctionBegin;

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

    589:   if (!viewer) PetscCall(PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)lg), &viewer));
    590:   PetscCall(PetscObjectPrintClassNamePrefixType((PetscObject)lg, viewer));
    591:   for (i = 0; i < dim; i++) {
    592:     PetscCall(PetscViewerASCIIPrintf(viewer, "Line %" PetscInt_FMT ">\n", i));
    593:     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]));
    594:   }
    595:   PetscFunctionReturn(PETSC_SUCCESS);
    596: }

    598: /*@
    599:   PetscDrawLGSetOptionsPrefix - Sets the prefix used for searching for all
    600:   `PetscDrawLG` options in the database.

    602:   Logically Collective

    604:   Input Parameters:
    605: + lg     - the line graph context
    606: - prefix - the prefix to prepend to all option names

    608:   Level: advanced

    610: .seealso: `PetscDrawLG`, `PetscDrawLGSetFromOptions()`, `PetscDrawLGCreate()`
    611: @*/
    612: PetscErrorCode PetscDrawLGSetOptionsPrefix(PetscDrawLG lg, const char prefix[])
    613: {
    614:   PetscFunctionBegin;
    616:   PetscCall(PetscObjectSetOptionsPrefix((PetscObject)lg, prefix));
    617:   PetscFunctionReturn(PETSC_SUCCESS);
    618: }

    620: /*@
    621:   PetscDrawLGSetFromOptions - Sets options related to the line graph object

    623:   Collective

    625:   Input Parameters:
    626: . lg - the line graph context

    628:   Options Database Key:
    629: . -lg_use_markers (true|false) - true means it draws a marker for each point

    631:   Level: intermediate

    633: .seealso: `PetscDrawLG`, `PetscDrawLGDestroy()`, `PetscDrawLGCreate()`
    634: @*/
    635: PetscErrorCode PetscDrawLGSetFromOptions(PetscDrawLG lg)
    636: {
    637:   PetscBool           usemarkers, set;
    638:   PetscDrawMarkerType markertype;

    640:   PetscFunctionBegin;

    643:   PetscCall(PetscDrawGetMarkerType(lg->win, &markertype));
    644:   PetscCall(PetscOptionsGetEnum(((PetscObject)lg)->options, ((PetscObject)lg)->prefix, "-lg_marker_type", PetscDrawMarkerTypes, (PetscEnum *)&markertype, &set));
    645:   if (set) {
    646:     PetscCall(PetscDrawLGSetUseMarkers(lg, PETSC_TRUE));
    647:     PetscCall(PetscDrawSetMarkerType(lg->win, markertype));
    648:   }
    649:   usemarkers = lg->use_markers;
    650:   PetscCall(PetscOptionsGetBool(((PetscObject)lg)->options, ((PetscObject)lg)->prefix, "-lg_use_markers", &usemarkers, &set));
    651:   if (set) PetscCall(PetscDrawLGSetUseMarkers(lg, usemarkers));
    652:   PetscFunctionReturn(PETSC_SUCCESS);
    653: }