Actual source code: svdmon.c

      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-, 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:    SVD routines related to monitors
     12: */

     14: #include <slepc/private/svdimpl.h>
     15: #include <petscdraw.h>

     17: /*
     18:    Runs the user provided monitor routines, if any.
     19: */
     20: PetscErrorCode SVDMonitor(SVD svd,PetscInt it,PetscInt nconv,PetscReal *sigma,PetscReal *errest,PetscInt nest)
     21: {
     22:   PetscInt       i,n = svd->numbermonitors;

     24:   PetscFunctionBegin;
     25:   for (i=0;i<n;i++) PetscCall((*svd->monitor[i])(svd,it,nconv,sigma,errest,nest,svd->monitorcontext[i]));
     26:   PetscFunctionReturn(PETSC_SUCCESS);
     27: }

     29: /*@C
     30:    SVDMonitorSet - Sets an ADDITIONAL function to be called at every
     31:    iteration to monitor the error estimates for each requested singular triplet.

     33:    Logically Collective

     35:    Input Parameters:
     36: +  svd            - the singular value solver context
     37: .  monitor        - pointer to function (if this is `NULL`, it turns off monitoring),
     38:                     see `SVDMonitorFn`
     39: .  mctx           - [optional] context for private data for the monitor routine
     40:                     (use `NULL` if no context is desired)
     41: -  monitordestroy - [optional] routine that frees monitor context (may be `NULL`),
     42:                     see `PetscCtxDestroyFn` for the calling sequence

     44:    Options Database Keys:
     45: +  -svd_monitor                    - print only the first error estimate
     46: .  -svd_monitor_all                - print error estimates at each iteration
     47: .  -svd_monitor_conv               - print the singular value approximations only when
     48:                                      convergence has been reached
     49: .  -svd_monitor_conditioning       - print the condition number when available
     50: .  -svd_monitor draw::draw_lg      - sets line graph monitor for the first unconverged
     51:                                      approximate singular value
     52: .  -svd_monitor_all draw::draw_lg  - sets line graph monitor for all unconverged
     53:                                      approximate singular values
     54: .  -svd_monitor_conv draw::draw_lg - sets line graph monitor for convergence history
     55: -  -svd_monitor_cancel             - cancels all monitors that have been hardwired into
     56:                                      a code by calls to `SVDMonitorSet()`, but does not cancel
     57:                                      those set via the options database.

     59:    Notes:
     60:    The options database option `-svd_monitor` and related options are the easiest way
     61:    to turn on `SVD` iteration monitoring.

     63:    `SVDMonitorRegister()` provides a way to associate an options database key with `SVD`
     64:    monitor function.

     66:    Several different monitoring routines may be set by calling `SVDMonitorSet()` multiple
     67:    times; all will be called in the order in which they were set.

     69:    Fortran Note:
     70:    Only a single monitor function can be set for each `SVD` object.

     72:    Level: intermediate

     74: .seealso: [](ch:svd), `SVDMonitorFirst()`, `SVDMonitorAll()`, `SVDMonitorConverged()`, `SVDMonitorConditioning()`, `SVDMonitorFirstDrawLG()`, `SVDMonitorAllDrawLG()`, `SVDMonitorConvergedDrawLG()`, `SVDMonitorCancel()`
     75: @*/
     76: PetscErrorCode SVDMonitorSet(SVD svd,SVDMonitorFn *monitor,void *mctx,PetscCtxDestroyFn *monitordestroy)
     77: {
     78:   PetscInt  i;
     79:   PetscBool identical;

     81:   PetscFunctionBegin;
     83:   for (i=0;i<svd->numbermonitors;i++) {
     84:     PetscCall(PetscMonitorCompare((PetscErrorCode(*)(void))(PetscVoidFn*)monitor,mctx,monitordestroy,(PetscErrorCode (*)(void))(PetscVoidFn*)svd->monitor[i],svd->monitorcontext[i],svd->monitordestroy[i],&identical));
     85:     if (identical) PetscFunctionReturn(PETSC_SUCCESS);
     86:   }
     87:   PetscCheck(svd->numbermonitors<MAXSVDMONITORS,PetscObjectComm((PetscObject)svd),PETSC_ERR_ARG_OUTOFRANGE,"Too many SVD monitors set");
     88:   svd->monitor[svd->numbermonitors]           = monitor;
     89:   svd->monitorcontext[svd->numbermonitors]    = mctx;
     90:   svd->monitordestroy[svd->numbermonitors++]  = monitordestroy;
     91:   PetscFunctionReturn(PETSC_SUCCESS);
     92: }

     94: /*@
     95:    SVDMonitorCancel - Clears all monitors for an `SVD` object.

     97:    Logically Collective

     99:    Input Parameter:
    100: .  svd - the singular value solver context

    102:    Options Database Key:
    103: .  -svd_monitor_cancel - cancels all monitors that have been hardwired into a code by calls to
    104:                          `SVDMonitorSet()`, but does not cancel those set via the options database.

    106:    Level: intermediate

    108: .seealso: [](ch:svd), `SVDMonitorSet()`
    109: @*/
    110: PetscErrorCode SVDMonitorCancel(SVD svd)
    111: {
    112:   PetscInt       i;

    114:   PetscFunctionBegin;
    116:   for (i=0; i<svd->numbermonitors; i++) {
    117:     if (svd->monitordestroy[i]) PetscCall((*svd->monitordestroy[i])(&svd->monitorcontext[i]));
    118:   }
    119:   svd->numbermonitors = 0;
    120:   PetscFunctionReturn(PETSC_SUCCESS);
    121: }

    123: /*@C
    124:    SVDGetMonitorContext - Gets the monitor context, as set by
    125:    `SVDMonitorSet()` for the FIRST monitor only.

    127:    Not Collective

    129:    Input Parameter:
    130: .  svd - the singular value solver context

    132:    Output Parameter:
    133: .  ctx - monitor context

    135:    Level: intermediate

    137: .seealso: [](ch:svd), `SVDMonitorSet()`
    138: @*/
    139: PetscErrorCode SVDGetMonitorContext(SVD svd,void *ctx)
    140: {
    141:   PetscFunctionBegin;
    143:   *(void**)ctx = svd->monitorcontext[0];
    144:   PetscFunctionReturn(PETSC_SUCCESS);
    145: }

    147: /*@C
    148:    SVDMonitorFirst - Print the first unconverged approximate value and
    149:    error estimate at each iteration of the singular value solver.

    151:    Collective

    153:    Input Parameters:
    154: +  svd    - the singular value solver context
    155: .  its    - iteration number
    156: .  nconv  - number of converged singular triplets so far
    157: .  sigma  - singular values
    158: .  errest - error estimates
    159: .  nest   - number of error estimates to display
    160: -  vf     - viewer and format for monitoring

    162:    Options Database Key:
    163: .  -svd_monitor - activates `SVDMonitorFirst()`

    165:    Note:
    166:    This is not called directly by users, rather one calls `SVDMonitorSet()`, with this
    167:    function as an argument, to cause the monitor to be used during the `SVD` solve.

    169:    Level: intermediate

    171: .seealso: [](ch:svd), `SVDMonitorSet()`, `SVDMonitorAll()`, `SVDMonitorConditioning()`, `SVDMonitorConverged()`
    172: @*/
    173: PetscErrorCode SVDMonitorFirst(SVD svd,PetscInt its,PetscInt nconv,PetscReal sigma[],PetscReal errest[],PetscInt nest,PetscViewerAndFormat *vf)
    174: {
    175:   PetscViewer    viewer = vf->viewer;

    177:   PetscFunctionBegin;
    180:   if (its==1 && ((PetscObject)svd)->prefix) PetscCall(PetscViewerASCIIPrintf(viewer,"  Singular value approximations and residual norms for %s solve.\n",((PetscObject)svd)->prefix));
    181:   if (nconv<nest) {
    182:     PetscCall(PetscViewerPushFormat(viewer,vf->format));
    183:     PetscCall(PetscViewerASCIIAddTab(viewer,((PetscObject)svd)->tablevel));
    184:     PetscCall(PetscViewerASCIIPrintf(viewer,"%3" PetscInt_FMT " SVD nconv=%" PetscInt_FMT " first unconverged value (error)",its,nconv));
    185:     PetscCall(PetscViewerASCIIUseTabs(viewer,PETSC_FALSE));
    186:     PetscCall(PetscViewerASCIIPrintf(viewer," %g (%10.8e)\n",(double)sigma[nconv],(double)errest[nconv]));
    187:     PetscCall(PetscViewerASCIIUseTabs(viewer,PETSC_TRUE));
    188:     PetscCall(PetscViewerASCIISubtractTab(viewer,((PetscObject)svd)->tablevel));
    189:     PetscCall(PetscViewerPopFormat(viewer));
    190:   }
    191:   PetscFunctionReturn(PETSC_SUCCESS);
    192: }

    194: /*@C
    195:    SVDMonitorAll - Print the current approximate values and
    196:    error estimates at each iteration of the singular value solver.

    198:    Collective

    200:    Input Parameters:
    201: +  svd    - the singular value solver context
    202: .  its    - iteration number
    203: .  nconv  - number of converged singular triplets so far
    204: .  sigma  - singular values
    205: .  errest - error estimates
    206: .  nest   - number of error estimates to display
    207: -  vf     - viewer and format for monitoring

    209:    Options Database Key:
    210: .  -svd_monitor_all - activates `SVDMonitorAll()`

    212:    Note:
    213:    This is not called directly by users, rather one calls `SVDMonitorSet()`, with this
    214:    function as an argument, to cause the monitor to be used during the `SVD` solve.

    216:    Level: intermediate

    218: .seealso: [](ch:svd), `SVDMonitorSet()`, `SVDMonitorFirst()`, `SVDMonitorConditioning()`, `SVDMonitorConverged()`
    219: @*/
    220: PetscErrorCode SVDMonitorAll(SVD svd,PetscInt its,PetscInt nconv,PetscReal sigma[],PetscReal errest[],PetscInt nest,PetscViewerAndFormat *vf)
    221: {
    222:   PetscInt       i;
    223:   PetscViewer    viewer = vf->viewer;

    225:   PetscFunctionBegin;
    228:   PetscCall(PetscViewerPushFormat(viewer,vf->format));
    229:   PetscCall(PetscViewerASCIIAddTab(viewer,((PetscObject)svd)->tablevel));
    230:   if (its==1 && ((PetscObject)svd)->prefix) PetscCall(PetscViewerASCIIPrintf(viewer,"  Singular value approximations and residual norms for %s solve.\n",((PetscObject)svd)->prefix));
    231:   PetscCall(PetscViewerASCIIPrintf(viewer,"%3" PetscInt_FMT " SVD nconv=%" PetscInt_FMT " Values (Errors)",its,nconv));
    232:   PetscCall(PetscViewerASCIIUseTabs(viewer,PETSC_FALSE));
    233:   for (i=0;i<nest;i++) PetscCall(PetscViewerASCIIPrintf(viewer," %g (%10.8e)",(double)sigma[i],(double)errest[i]));
    234:   PetscCall(PetscViewerASCIIPrintf(viewer,"\n"));
    235:   PetscCall(PetscViewerASCIIUseTabs(viewer,PETSC_TRUE));
    236:   PetscCall(PetscViewerASCIISubtractTab(viewer,((PetscObject)svd)->tablevel));
    237:   PetscCall(PetscViewerPopFormat(viewer));
    238:   PetscFunctionReturn(PETSC_SUCCESS);
    239: }

    241: /*@C
    242:    SVDMonitorConverged - Print the approximate values and
    243:    error estimates as they converge.

    245:    Collective

    247:    Input Parameters:
    248: +  svd    - the singular value solver context
    249: .  its    - iteration number
    250: .  nconv  - number of converged singular triplets so far
    251: .  sigma  - singular values
    252: .  errest - error estimates
    253: .  nest   - number of error estimates to display
    254: -  vf     - viewer and format for monitoring

    256:    Options Database Key:
    257: .  -svd_monitor_conv - activates `SVDMonitorConverged()`

    259:    Note:
    260:    This is not called directly by users, rather one calls `SVDMonitorSet()`, with this
    261:    function as an argument, to cause the monitor to be used during the `SVD` solve.

    263:    Level: intermediate

    265: .seealso: [](ch:svd), `SVDMonitorSet()`, `SVDMonitorFirst()`, `SVDMonitorConditioning()`, `SVDMonitorAll()`
    266: @*/
    267: PetscErrorCode SVDMonitorConverged(SVD svd,PetscInt its,PetscInt nconv,PetscReal sigma[],PetscReal errest[],PetscInt nest,PetscViewerAndFormat *vf)
    268: {
    269:   PetscInt       i;
    270:   PetscViewer    viewer = vf->viewer;
    271:   SlepcConvMon   ctx;

    273:   PetscFunctionBegin;
    276:   ctx = (SlepcConvMon)vf->data;
    277:   if (its==1 && ((PetscObject)svd)->prefix) PetscCall(PetscViewerASCIIPrintf(viewer,"  Convergence history for %s solve.\n",((PetscObject)svd)->prefix));
    278:   if (its==1) ctx->oldnconv = 0;
    279:   if (ctx->oldnconv!=nconv) {
    280:     PetscCall(PetscViewerPushFormat(viewer,vf->format));
    281:     PetscCall(PetscViewerASCIIAddTab(viewer,((PetscObject)svd)->tablevel));
    282:     for (i=ctx->oldnconv;i<nconv;i++) {
    283:       PetscCall(PetscViewerASCIIPrintf(viewer,"%3" PetscInt_FMT " SVD converged value (error) #%" PetscInt_FMT,its,i));
    284:       PetscCall(PetscViewerASCIIUseTabs(viewer,PETSC_FALSE));
    285:       PetscCall(PetscViewerASCIIPrintf(viewer," %g (%10.8e)\n",(double)sigma[i],(double)errest[i]));
    286:       PetscCall(PetscViewerASCIIUseTabs(viewer,PETSC_TRUE));
    287:     }
    288:     PetscCall(PetscViewerASCIISubtractTab(viewer,((PetscObject)svd)->tablevel));
    289:     PetscCall(PetscViewerPopFormat(viewer));
    290:     ctx->oldnconv = nconv;
    291:   }
    292:   PetscFunctionReturn(PETSC_SUCCESS);
    293: }

    295: PetscErrorCode SVDMonitorConvergedCreate(PetscViewer viewer,PetscViewerFormat format,void *ctx,PetscViewerAndFormat **vf)
    296: {
    297:   SlepcConvMon   mctx;

    299:   PetscFunctionBegin;
    300:   PetscCall(PetscViewerAndFormatCreate(viewer,format,vf));
    301:   PetscCall(PetscNew(&mctx));
    302:   mctx->ctx = ctx;
    303:   (*vf)->data = (void*)mctx;
    304:   PetscFunctionReturn(PETSC_SUCCESS);
    305: }

    307: PetscErrorCode SVDMonitorConvergedDestroy(PetscViewerAndFormat **vf)
    308: {
    309:   PetscFunctionBegin;
    310:   if (!*vf) PetscFunctionReturn(PETSC_SUCCESS);
    311:   PetscCall(PetscFree((*vf)->data));
    312:   PetscCall(PetscViewerDestroy(&(*vf)->viewer));
    313:   PetscCall(PetscFree(*vf));
    314:   PetscFunctionReturn(PETSC_SUCCESS);
    315: }

    317: /*@C
    318:    SVDMonitorFirstDrawLG - Plots the error estimate of the first unconverged
    319:    approximation at each iteration of the singular value solver.

    321:    Collective

    323:    Input Parameters:
    324: +  svd    - the singular value solver context
    325: .  its    - iteration number
    326: .  nconv  - number of converged singular triplets so far
    327: .  sigma  - singular values
    328: .  errest - error estimates
    329: .  nest   - number of error estimates to display
    330: -  vf     - viewer and format for monitoring

    332:    Options Database Key:
    333: .  -svd_monitor draw::draw_lg - activates `SVDMonitorFirstDrawLG()`

    335:    Notes:
    336:    This is not called directly by users, rather one calls `SVDMonitorSet()`, with this
    337:    function as an argument, to cause the monitor to be used during the `SVD` solve.

    339:    Call `SVDMonitorFirstDrawLGCreate()` to create the context used with this monitor.

    341:    Level: intermediate

    343: .seealso: [](ch:svd), `SVDMonitorSet()`, `SVDMonitorFirstDrawLGCreate()`
    344: @*/
    345: PetscErrorCode SVDMonitorFirstDrawLG(SVD svd,PetscInt its,PetscInt nconv,PetscReal sigma[],PetscReal errest[],PetscInt nest,PetscViewerAndFormat *vf)
    346: {
    347:   PetscViewer    viewer = vf->viewer;
    348:   PetscDrawLG    lg;
    349:   PetscReal      x,y;

    351:   PetscFunctionBegin;
    354:   PetscCall(PetscViewerPushFormat(viewer,vf->format));
    355:   PetscCall(PetscViewerDrawGetDrawLG(viewer,0,&lg));
    356:   if (its==1) {
    357:     PetscCall(PetscDrawLGReset(lg));
    358:     PetscCall(PetscDrawLGSetDimension(lg,1));
    359:     PetscCall(PetscDrawLGSetLimits(lg,1,1,PetscLog10Real(svd->tol)-2,0.0));
    360:   }
    361:   if (nconv<nest) {
    362:     x = (PetscReal)its;
    363:     if (errest[nconv] > 0.0) y = PetscLog10Real(errest[nconv]);
    364:     else y = 0.0;
    365:     PetscCall(PetscDrawLGAddPoint(lg,&x,&y));
    366:     if (its <= 20 || !(its % 5) || svd->reason) {
    367:       PetscCall(PetscDrawLGDraw(lg));
    368:       PetscCall(PetscDrawLGSave(lg));
    369:     }
    370:   }
    371:   PetscCall(PetscViewerPopFormat(viewer));
    372:   PetscFunctionReturn(PETSC_SUCCESS);
    373: }

    375: /*@C
    376:    SVDMonitorFirstDrawLGCreate - Creates the plotter for the first error estimate.

    378:    Collective

    380:    Input Parameters:
    381: +  viewer - the viewer
    382: .  format - the viewer format
    383: -  ctx    - an optional user context

    385:    Output Parameter:
    386: .  vf     - the viewer and format context

    388:    Level: intermediate

    390: .seealso: [](ch:svd), `SVDMonitorSet()`
    391: @*/
    392: PetscErrorCode SVDMonitorFirstDrawLGCreate(PetscViewer viewer,PetscViewerFormat format,void *ctx,PetscViewerAndFormat **vf)
    393: {
    394:   PetscFunctionBegin;
    395:   PetscCall(PetscViewerAndFormatCreate(viewer,format,vf));
    396:   (*vf)->data = ctx;
    397:   PetscCall(PetscViewerMonitorLGSetUp(viewer,NULL,"First Error Estimate","Log Error Estimate",1,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300));
    398:   PetscFunctionReturn(PETSC_SUCCESS);
    399: }

    401: /*@C
    402:    SVDMonitorAllDrawLG - Plots the error estimate of all unconverged
    403:    approximations at each iteration of the singular value solver.

    405:    Collective

    407:    Input Parameters:
    408: +  svd    - the singular value solver context
    409: .  its    - iteration number
    410: .  nconv  - number of converged singular triplets so far
    411: .  sigma  - singular values
    412: .  errest - error estimates
    413: .  nest   - number of error estimates to display
    414: -  vf     - viewer and format for monitoring

    416:    Options Database Key:
    417: .  -svd_monitor_all draw::draw_lg - activates `SVDMonitorAllDrawLG()`

    419:    Notes:
    420:    This is not called directly by users, rather one calls `SVDMonitorSet()`, with this
    421:    function as an argument, to cause the monitor to be used during the `SVD` solve.

    423:    Call `SVDMonitorAllDrawLGCreate()` to create the context used with this monitor.

    425:    Level: intermediate

    427: .seealso: [](ch:svd), `SVDMonitorSet()`, `SVDMonitorAllDrawLGCreate()`
    428: @*/
    429: PetscErrorCode SVDMonitorAllDrawLG(SVD svd,PetscInt its,PetscInt nconv,PetscReal sigma[],PetscReal errest[],PetscInt nest,PetscViewerAndFormat *vf)
    430: {
    431:   PetscViewer    viewer = vf->viewer;
    432:   PetscDrawLG    lg;
    433:   PetscInt       i,n = PetscMin(svd->nsv,255);
    434:   PetscReal      *x,*y;

    436:   PetscFunctionBegin;
    439:   PetscCall(PetscViewerPushFormat(viewer,vf->format));
    440:   PetscCall(PetscViewerDrawGetDrawLG(viewer,0,&lg));
    441:   if (its==1) {
    442:     PetscCall(PetscDrawLGReset(lg));
    443:     PetscCall(PetscDrawLGSetDimension(lg,n));
    444:     PetscCall(PetscDrawLGSetLimits(lg,1,1,PetscLog10Real(svd->tol)-2,0.0));
    445:   }
    446:   PetscCall(PetscMalloc2(n,&x,n,&y));
    447:   for (i=0;i<n;i++) {
    448:     x[i] = (PetscReal)its;
    449:     if (i < nest && errest[i] > 0.0) y[i] = PetscLog10Real(errest[i]);
    450:     else y[i] = 0.0;
    451:   }
    452:   PetscCall(PetscDrawLGAddPoint(lg,x,y));
    453:   if (its <= 20 || !(its % 5) || svd->reason) {
    454:     PetscCall(PetscDrawLGDraw(lg));
    455:     PetscCall(PetscDrawLGSave(lg));
    456:   }
    457:   PetscCall(PetscFree2(x,y));
    458:   PetscCall(PetscViewerPopFormat(viewer));
    459:   PetscFunctionReturn(PETSC_SUCCESS);
    460: }

    462: /*@C
    463:    SVDMonitorAllDrawLGCreate - Creates the plotter for all the error estimates.

    465:    Collective

    467:    Input Parameters:
    468: +  viewer - the viewer
    469: .  format - the viewer format
    470: -  ctx    - an optional user context

    472:    Output Parameter:
    473: .  vf     - the viewer and format context

    475:    Level: intermediate

    477: .seealso: [](ch:svd), `SVDMonitorSet()`
    478: @*/
    479: PetscErrorCode SVDMonitorAllDrawLGCreate(PetscViewer viewer,PetscViewerFormat format,void *ctx,PetscViewerAndFormat **vf)
    480: {
    481:   PetscFunctionBegin;
    482:   PetscCall(PetscViewerAndFormatCreate(viewer,format,vf));
    483:   (*vf)->data = ctx;
    484:   PetscCall(PetscViewerMonitorLGSetUp(viewer,NULL,"All Error Estimates","Log Error Estimate",1,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300));
    485:   PetscFunctionReturn(PETSC_SUCCESS);
    486: }

    488: /*@C
    489:    SVDMonitorConvergedDrawLG - Plots the number of converged eigenvalues
    490:    at each iteration of the singular value solver.

    492:    Collective

    494:    Input Parameters:
    495: +  svd    - the singular value solver context
    496: .  its    - iteration number
    497: .  nconv  - number of converged singular triplets so far
    498: .  sigma  - singular values
    499: .  errest - error estimates
    500: .  nest   - number of error estimates to display
    501: -  vf     - viewer and format for monitoring

    503:    Options Database Key:
    504: .  -svd_monitor_conv draw::draw_lg - activates `SVDMonitorConvergedDrawLG()`

    506:    Notes:
    507:    This is not called directly by users, rather one calls `SVDMonitorSet()`, with this
    508:    function as an argument, to cause the monitor to be used during the `SVD` solve.

    510:    Call `SVDMonitorConvergedDrawLGCreate()` to create the context used with this monitor.

    512:    Level: intermediate

    514: .seealso: [](ch:svd), `SVDMonitorSet()`, `SVDMonitorConvergedDrawLGCreate()`
    515: @*/
    516: PetscErrorCode SVDMonitorConvergedDrawLG(SVD svd,PetscInt its,PetscInt nconv,PetscReal sigma[],PetscReal errest[],PetscInt nest,PetscViewerAndFormat *vf)
    517: {
    518:   PetscViewer      viewer = vf->viewer;
    519:   PetscDrawLG      lg;
    520:   PetscReal        x,y;

    522:   PetscFunctionBegin;
    525:   PetscCall(PetscViewerPushFormat(viewer,vf->format));
    526:   PetscCall(PetscViewerDrawGetDrawLG(viewer,0,&lg));
    527:   if (its==1) {
    528:     PetscCall(PetscDrawLGReset(lg));
    529:     PetscCall(PetscDrawLGSetDimension(lg,1));
    530:     PetscCall(PetscDrawLGSetLimits(lg,1,1,0,svd->nsv));
    531:   }
    532:   x = (PetscReal)its;
    533:   y = (PetscReal)svd->nconv;
    534:   PetscCall(PetscDrawLGAddPoint(lg,&x,&y));
    535:   if (its <= 20 || !(its % 5) || svd->reason) {
    536:     PetscCall(PetscDrawLGDraw(lg));
    537:     PetscCall(PetscDrawLGSave(lg));
    538:   }
    539:   PetscCall(PetscViewerPopFormat(viewer));
    540:   PetscFunctionReturn(PETSC_SUCCESS);
    541: }

    543: /*@C
    544:    SVDMonitorConvergedDrawLGCreate - Creates the plotter for the convergence history.

    546:    Collective

    548:    Input Parameters:
    549: +  viewer - the viewer
    550: .  format - the viewer format
    551: -  ctx    - an optional user context

    553:    Output Parameter:
    554: .  vf     - the viewer and format context

    556:    Level: intermediate

    558: .seealso: [](ch:svd), `SVDMonitorSet()`
    559: @*/
    560: PetscErrorCode SVDMonitorConvergedDrawLGCreate(PetscViewer viewer,PetscViewerFormat format,void *ctx,PetscViewerAndFormat **vf)
    561: {
    562:   SlepcConvMon   mctx;

    564:   PetscFunctionBegin;
    565:   PetscCall(PetscViewerAndFormatCreate(viewer,format,vf));
    566:   PetscCall(PetscNew(&mctx));
    567:   mctx->ctx = ctx;
    568:   (*vf)->data = (void*)mctx;
    569:   PetscCall(PetscViewerMonitorLGSetUp(viewer,NULL,"Convergence History","Number Converged",1,NULL,PETSC_DECIDE,PETSC_DECIDE,400,300));
    570:   PetscFunctionReturn(PETSC_SUCCESS);
    571: }

    573: /*@C
    574:    SVDMonitorConditioning - Print the condition number at each iteration of the singular
    575:    value solver.

    577:    Collective

    579:    Input Parameters:
    580: +  svd    - the singular value solver context
    581: .  its    - iteration number
    582: .  nconv  - (unused) number of converged singular triplets so far
    583: .  sigma  - (unused) singular values
    584: .  errest - (unused) error estimates
    585: .  nest   - (unused) number of error estimates to display
    586: -  vf     - viewer and format for monitoring

    588:    Options Database Key:
    589: .  -svd_monitor_conditioning - activates `SVDMonitorConditioning()`

    591:    Notes:
    592:    This is not called directly by users, rather one calls `SVDMonitorSet()`, with this
    593:    function as an argument, to cause the monitor to be used during the `SVD` solve.

    595:    Works only for solvers that use a `DS` of type `DSGSVD`. The printed information corresponds
    596:    to the maximum of the condition number of the two generated bidiagonal matrices.

    598:    Level: intermediate

    600: .seealso: [](ch:svd), `SVDMonitorSet()`, `SVDMonitorAll()`, `SVDMonitorFirst()`, `SVDMonitorConverged()`
    601: @*/
    602: PetscErrorCode SVDMonitorConditioning(SVD svd,PetscInt its,PetscInt nconv,PetscReal sigma[],PetscReal errest[],PetscInt nest,PetscViewerAndFormat *vf)
    603: {
    604:   PetscViewer viewer = vf->viewer;
    605:   PetscBool   isgsvd;
    606:   PetscReal   cond;

    608:   PetscFunctionBegin;
    611:   PetscCall(PetscObjectTypeCompare((PetscObject)svd->ds,DSGSVD,&isgsvd));
    612:   if (!isgsvd) PetscFunctionReturn(PETSC_SUCCESS);
    613:   if (its==1 && ((PetscObject)svd)->prefix) PetscCall(PetscViewerASCIIPrintf(viewer,"  Condition number of bidiagonal matrices for %s solve.\n",((PetscObject)svd)->prefix));
    614:   PetscCall(PetscViewerPushFormat(viewer,vf->format));
    615:   PetscCall(PetscViewerASCIIAddTab(viewer,((PetscObject)svd)->tablevel));
    616:   PetscCall(DSCond(svd->ds,&cond));
    617:   PetscCall(PetscViewerASCIIPrintf(viewer,"%3" PetscInt_FMT " SVD condition number = %g\n",its,(double)cond));
    618:   PetscCall(PetscViewerASCIISubtractTab(viewer,((PetscObject)svd)->tablevel));
    619:   PetscCall(PetscViewerPopFormat(viewer));
    620:   PetscFunctionReturn(PETSC_SUCCESS);
    621: }