1 2 #include <petsc/private/tsimpl.h> /*I "petscts.h" I*/ 3 #include <petscdraw.h> 4 5 /* ------------------------------------------------------------------------*/ 6 struct _n_TSMonitorSPEigCtx { 7 PetscDrawSP drawsp; 8 KSP ksp; 9 PetscInt howoften; /* when > 0 uses step % howoften, when negative only final solution plotted */ 10 PetscBool computeexplicitly; 11 MPI_Comm comm; 12 PetscRandom rand; 13 PetscReal xmin,xmax,ymin,ymax; 14 }; 15 16 17 /*@C 18 TSMonitorSPEigCtxCreate - Creates a context for use with TS to monitor the eigenvalues of the linearized operator 19 20 Collective on TS 21 22 Input Parameters: 23 + host - the X display to open, or null for the local machine 24 . label - the title to put in the title bar 25 . x, y - the screen coordinates of the upper left coordinate of the window 26 . m, n - the screen width and height in pixels 27 - howoften - if positive then determines the frequency of the plotting, if -1 then only at the final time 28 29 Output Parameter: 30 . ctx - the context 31 32 Options Database Key: 33 . -ts_monitor_sp_eig - plot egienvalues of linearized right hand side 34 35 Notes: 36 Use TSMonitorSPEigCtxDestroy() to destroy. 37 38 Currently only works if the Jacobian is provided explicitly. 39 40 Currently only works for ODEs u_t - F(t,u) = 0; that is with no mass matrix. 41 42 Level: intermediate 43 44 .keywords: TS, monitor, line graph, residual, seealso 45 46 .seealso: TSMonitorSPEigTimeStep(), TSMonitorSet(), TSMonitorLGSolution(), TSMonitorLGError() 47 48 @*/ 49 PetscErrorCode TSMonitorSPEigCtxCreate(MPI_Comm comm,const char host[],const char label[],int x,int y,int m,int n,PetscInt howoften,TSMonitorSPEigCtx *ctx) 50 { 51 PetscDraw win; 52 PetscErrorCode ierr; 53 PC pc; 54 55 PetscFunctionBegin; 56 ierr = PetscNew(ctx);CHKERRQ(ierr); 57 ierr = PetscRandomCreate(comm,&(*ctx)->rand);CHKERRQ(ierr); 58 ierr = PetscRandomSetFromOptions((*ctx)->rand);CHKERRQ(ierr); 59 ierr = PetscDrawCreate(comm,host,label,x,y,m,n,&win);CHKERRQ(ierr); 60 ierr = PetscDrawSetFromOptions(win);CHKERRQ(ierr); 61 ierr = PetscDrawSPCreate(win,1,&(*ctx)->drawsp);CHKERRQ(ierr); 62 ierr = KSPCreate(comm,&(*ctx)->ksp);CHKERRQ(ierr); 63 ierr = KSPSetOptionsPrefix((*ctx)->ksp,"ts_monitor_sp_eig_");CHKERRQ(ierr); /* this is wrong, used use also prefix from the TS */ 64 ierr = KSPSetType((*ctx)->ksp,KSPGMRES);CHKERRQ(ierr); 65 ierr = KSPGMRESSetRestart((*ctx)->ksp,200);CHKERRQ(ierr); 66 ierr = KSPSetTolerances((*ctx)->ksp,1.e-10,PETSC_DEFAULT,PETSC_DEFAULT,200);CHKERRQ(ierr); 67 ierr = KSPSetComputeSingularValues((*ctx)->ksp,PETSC_TRUE);CHKERRQ(ierr); 68 ierr = KSPSetFromOptions((*ctx)->ksp);CHKERRQ(ierr); 69 ierr = KSPGetPC((*ctx)->ksp,&pc);CHKERRQ(ierr); 70 ierr = PCSetType(pc,PCNONE);CHKERRQ(ierr); 71 72 (*ctx)->howoften = howoften; 73 (*ctx)->computeexplicitly = PETSC_FALSE; 74 75 ierr = PetscOptionsGetBool(NULL,NULL,"-ts_monitor_sp_eig_explicitly",&(*ctx)->computeexplicitly,NULL);CHKERRQ(ierr); 76 77 (*ctx)->comm = comm; 78 (*ctx)->xmin = -2.1; 79 (*ctx)->xmax = 1.1; 80 (*ctx)->ymin = -1.1; 81 (*ctx)->ymax = 1.1; 82 PetscFunctionReturn(0); 83 } 84 85 static PetscErrorCode TSLinearStabilityIndicator(TS ts, PetscReal xr,PetscReal xi,PetscBool *flg) 86 { 87 PetscErrorCode ierr; 88 PetscReal yr,yi; 89 90 PetscFunctionBegin; 91 ierr = TSComputeLinearStability(ts,xr,xi,&yr,&yi);CHKERRQ(ierr); 92 if ((yr*yr + yi*yi) <= 1.0) *flg = PETSC_TRUE; 93 else *flg = PETSC_FALSE; 94 PetscFunctionReturn(0); 95 } 96 97 PetscErrorCode TSMonitorSPEig(TS ts,PetscInt step,PetscReal ptime,Vec v,void *monctx) 98 { 99 TSMonitorSPEigCtx ctx = (TSMonitorSPEigCtx) monctx; 100 PetscErrorCode ierr; 101 KSP ksp = ctx->ksp; 102 PetscInt n,N,nits,neig,i,its = 200; 103 PetscReal *r,*c,time_step_save; 104 PetscDrawSP drawsp = ctx->drawsp; 105 Mat A,B; 106 Vec xdot; 107 SNES snes; 108 109 PetscFunctionBegin; 110 if (step < 0) PetscFunctionReturn(0); /* -1 indicates interpolated solution */ 111 if (!step) PetscFunctionReturn(0); 112 if (((ctx->howoften > 0) && (!(step % ctx->howoften))) || ((ctx->howoften == -1) && ts->reason)) { 113 ierr = VecDuplicate(v,&xdot);CHKERRQ(ierr); 114 ierr = TSGetSNES(ts,&snes);CHKERRQ(ierr); 115 ierr = SNESGetJacobian(snes,&A,&B,NULL,NULL);CHKERRQ(ierr); 116 ierr = MatDuplicate(A,MAT_DO_NOT_COPY_VALUES,&B);CHKERRQ(ierr); 117 /* 118 This doesn't work because methods keep and use internal information about the shift so it 119 seems we would need code for each method to trick the correct Jacobian in being computed. 120 */ 121 time_step_save = ts->time_step; 122 ts->time_step = PETSC_MAX_REAL; 123 124 ierr = SNESComputeJacobian(snes,v,A,B);CHKERRQ(ierr); 125 126 ts->time_step = time_step_save; 127 128 ierr = KSPSetOperators(ksp,B,B);CHKERRQ(ierr); 129 ierr = VecGetSize(v,&n);CHKERRQ(ierr); 130 if (n < 200) its = n; 131 ierr = KSPSetTolerances(ksp,1.e-10,PETSC_DEFAULT,PETSC_DEFAULT,its);CHKERRQ(ierr); 132 ierr = VecSetRandom(xdot,ctx->rand);CHKERRQ(ierr); 133 ierr = KSPSolve(ksp,xdot,xdot);CHKERRQ(ierr); 134 ierr = VecDestroy(&xdot);CHKERRQ(ierr); 135 ierr = KSPGetIterationNumber(ksp,&nits);CHKERRQ(ierr); 136 N = nits+2; 137 138 if (nits) { 139 PetscDraw draw; 140 PetscReal pause; 141 PetscDrawAxis axis; 142 PetscReal xmin,xmax,ymin,ymax; 143 144 ierr = PetscDrawSPReset(drawsp);CHKERRQ(ierr); 145 ierr = PetscDrawSPSetLimits(drawsp,ctx->xmin,ctx->xmax,ctx->ymin,ctx->ymax);CHKERRQ(ierr); 146 ierr = PetscMalloc2(PetscMax(n,N),&r,PetscMax(n,N),&c);CHKERRQ(ierr); 147 if (ctx->computeexplicitly) { 148 ierr = KSPComputeEigenvaluesExplicitly(ksp,n,r,c);CHKERRQ(ierr); 149 neig = n; 150 } else { 151 ierr = KSPComputeEigenvalues(ksp,N,r,c,&neig);CHKERRQ(ierr); 152 } 153 /* We used the positive operator to be able to reuse KSPs that require positive definiteness, now flip the spectrum as is conventional for ODEs */ 154 for (i=0; i<neig; i++) r[i] = -r[i]; 155 for (i=0; i<neig; i++) { 156 if (ts->ops->linearstability) { 157 PetscReal fr,fi; 158 ierr = TSComputeLinearStability(ts,r[i],c[i],&fr,&fi);CHKERRQ(ierr); 159 if ((fr*fr + fi*fi) > 1.0) { 160 ierr = PetscPrintf(ctx->comm,"Linearized Eigenvalue %g + %g i linear stability function %g norm indicates unstable scheme \n",(double)r[i],(double)c[i],(double)(fr*fr + fi*fi));CHKERRQ(ierr); 161 } 162 } 163 ierr = PetscDrawSPAddPoint(drawsp,r+i,c+i);CHKERRQ(ierr); 164 } 165 ierr = PetscFree2(r,c);CHKERRQ(ierr); 166 ierr = PetscDrawSPGetDraw(drawsp,&draw);CHKERRQ(ierr); 167 ierr = PetscDrawGetPause(draw,&pause);CHKERRQ(ierr); 168 ierr = PetscDrawSetPause(draw,0.0);CHKERRQ(ierr); 169 ierr = PetscDrawSPDraw(drawsp,PETSC_TRUE);CHKERRQ(ierr); 170 ierr = PetscDrawSetPause(draw,pause);CHKERRQ(ierr); 171 if (ts->ops->linearstability) { 172 ierr = PetscDrawSPGetAxis(drawsp,&axis);CHKERRQ(ierr); 173 ierr = PetscDrawAxisGetLimits(axis,&xmin,&xmax,&ymin,&ymax);CHKERRQ(ierr); 174 ierr = PetscDrawIndicatorFunction(draw,xmin,xmax,ymin,ymax,PETSC_DRAW_CYAN,(PetscErrorCode (*)(void*,PetscReal,PetscReal,PetscBool*))TSLinearStabilityIndicator,ts);CHKERRQ(ierr); 175 ierr = PetscDrawSPDraw(drawsp,PETSC_FALSE);CHKERRQ(ierr); 176 } 177 ierr = PetscDrawSPSave(drawsp);CHKERRQ(ierr); 178 } 179 ierr = MatDestroy(&B);CHKERRQ(ierr); 180 } 181 PetscFunctionReturn(0); 182 } 183 184 /*@C 185 TSMonitorSPEigCtxDestroy - Destroys a scatter plot context that was created with TSMonitorSPEigCtxCreate(). 186 187 Collective on TSMonitorSPEigCtx 188 189 Input Parameter: 190 . ctx - the monitor context 191 192 Level: intermediate 193 194 .keywords: TS, monitor, line graph, destroy 195 196 .seealso: TSMonitorSPEigCtxCreate(), TSMonitorSet(), TSMonitorSPEig(); 197 @*/ 198 PetscErrorCode TSMonitorSPEigCtxDestroy(TSMonitorSPEigCtx *ctx) 199 { 200 PetscDraw draw; 201 PetscErrorCode ierr; 202 203 PetscFunctionBegin; 204 ierr = PetscDrawSPGetDraw((*ctx)->drawsp,&draw);CHKERRQ(ierr); 205 ierr = PetscDrawDestroy(&draw);CHKERRQ(ierr); 206 ierr = PetscDrawSPDestroy(&(*ctx)->drawsp);CHKERRQ(ierr); 207 ierr = KSPDestroy(&(*ctx)->ksp);CHKERRQ(ierr); 208 ierr = PetscRandomDestroy(&(*ctx)->rand);CHKERRQ(ierr); 209 ierr = PetscFree(*ctx);CHKERRQ(ierr); 210 PetscFunctionReturn(0); 211 } 212 213 214 215