/* collective on KSP */ PetscErrorCode KSPPlotEigenContours_Private(KSP ksp,PetscInt neig,const PetscReal *r,const PetscReal *c) { PetscErrorCode ierr; PetscReal xmin,xmax,ymin,ymax,*xloc,*yloc,*value,px0,py0,rscale,iscale; PetscInt M,N,i,j; PetscMPIInt rank; PetscViewer viewer; PetscDraw draw; PetscDrawAxis drawaxis; PetscFunctionBegin; ierr = MPI_Comm_rank(((PetscObject)ksp)->comm,&rank);CHKERRQ(ierr); if (rank) PetscFunctionReturn(0); M = 80; N = 80; xmin = r[0]; xmax = r[0]; ymin = c[0]; ymax = c[0]; for (i=1; i<neig; i++) { xmin = PetscMin(xmin,r[i]); xmax = PetscMax(xmax,r[i]); ymin = PetscMin(ymin,c[i]); ymax = PetscMax(ymax,c[i]); } ierr = PetscMalloc3(M,PetscReal,&xloc,N,PetscReal,&yloc,M*N,PetscReal,&value);CHKERRQ(ierr); for (i=0; i<M; i++) xloc[i] = xmin - 0.1*(xmax-xmin) + 1.2*(xmax-xmin)*i/(M-1); for (i=0; i<N; i++) yloc[i] = ymin - 0.1*(ymax-ymin) + 1.2*(ymax-ymin)*i/(N-1); ierr = PolyEval(neig,r,c,0,0,&px0,&py0);CHKERRQ(ierr); rscale = px0/(PetscSqr(px0)+PetscSqr(py0)); iscale = -py0/(PetscSqr(px0)+PetscSqr(py0)); for (j=0; j<N; j++) { for (i=0; i<M; i++) { PetscReal px,py,tx,ty,tmod; ierr = PolyEval(neig,r,c,xloc[i],yloc[j],&px,&py);CHKERRQ(ierr); tx = px*rscale - py*iscale; ty = py*rscale + px*iscale; tmod = PetscSqr(tx) + PetscSqr(ty); /* modulus of the complex polynomial */ if (tmod > 1) tmod = 1.0; if (tmod > 0.5 && tmod < 1) tmod = 0.5; if (tmod > 0.2 && tmod < 0.5) tmod = 0.2; if (tmod > 0.05 && tmod < 0.2) tmod = 0.05; if (tmod < 1e-3) tmod = 1e-3; value[i+j*M] = PetscLogScalar(tmod) / PetscLogScalar(10.0); } } ierr = PetscViewerDrawOpen(PETSC_COMM_SELF,0,"Iteratively Computed Eigen-contours",PETSC_DECIDE,PETSC_DECIDE,450,450,&viewer);CHKERRQ(ierr); ierr = PetscViewerDrawGetDraw(viewer,0,&draw);CHKERRQ(ierr); ierr = PetscDrawTensorContour(draw,M,N,PETSC_NULL,PETSC_NULL,value);CHKERRQ(ierr); if (0) { ierr = PetscDrawAxisCreate(draw,&drawaxis);CHKERRQ(ierr); ierr = PetscDrawAxisSetLimits(drawaxis,xmin,xmax,ymin,ymax);CHKERRQ(ierr); ierr = PetscDrawAxisSetLabels(drawaxis,"Eigen-counters","real","imag");CHKERRQ(ierr); ierr = PetscDrawAxisDraw(drawaxis);CHKERRQ(ierr); ierr = PetscDrawAxisDestroy(&drawaxis);CHKERRQ(ierr); } ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr); ierr = PetscFree3(xloc,yloc,value);CHKERRQ(ierr); PetscFunctionReturn(0); }
int main(int argc,char **argv) { PetscDrawLG lg; PetscErrorCode ierr; PetscInt Mx = 100,i; PetscReal x,hx = .1/Mx,pause,xx[3],yy[3]; PetscDraw draw; const char *const legend[] = {"(1 - u^2)^2","1 - u^2","-(1 - u)log(1 - u)"}; PetscDrawAxis axis; static PetscDrawViewPorts *ports = 0; PetscFunctionBegin; PetscInitialize(&argc,&argv,0,help); ierr = PetscViewerDrawResize(PETSC_VIEWER_DRAW_(PETSC_COMM_WORLD),1200,800);CHKERRQ(ierr); ierr = PetscViewerDrawGetDrawLG(PETSC_VIEWER_DRAW_(PETSC_COMM_WORLD),0,&lg);CHKERRQ(ierr); ierr = PetscDrawLGGetDraw(lg,&draw);CHKERRQ(ierr); ierr = PetscDrawCheckResizedWindow(draw);CHKERRQ(ierr); if (!ports) { ierr = PetscDrawViewPortsCreateRect(draw,1,2,&ports);CHKERRQ(ierr); } ierr = PetscDrawLGGetAxis(lg,&axis);CHKERRQ(ierr); ierr = PetscDrawLGReset(lg);CHKERRQ(ierr); /* Plot the energies */ ierr = PetscDrawLGSetDimension(lg,3);CHKERRQ(ierr); ierr = PetscDrawViewPortsSet(ports,1);CHKERRQ(ierr); x = .9; for (i=0; i<Mx; i++) { xx[0] = xx[1] = xx[2] = x; yy[0] = (1.-x*x)*(1. - x*x); yy[1] = (1. - x*x); yy[2] = -(1.-x)*PetscLogScalar(1.-x); ierr = PetscDrawLGAddPoint(lg,xx,yy);CHKERRQ(ierr); x += hx; } ierr = PetscDrawGetPause(draw,&pause);CHKERRQ(ierr); ierr = PetscDrawSetPause(draw,0.0);CHKERRQ(ierr); ierr = PetscDrawAxisSetLabels(axis,"Energy","","");CHKERRQ(ierr); ierr = PetscDrawLGSetLegend(lg,legend);CHKERRQ(ierr); ierr = PetscDrawLGDraw(lg);CHKERRQ(ierr); /* Plot the forces */ ierr = PetscDrawViewPortsSet(ports,0);CHKERRQ(ierr); ierr = PetscDrawLGReset(lg);CHKERRQ(ierr); x = .9; for (i=0; i<Mx; i++) { xx[0] = xx[1] = xx[2] = x; yy[0] = x*x*x - x; yy[1] = -x; yy[2] = 1.0 + PetscLogScalar(1. - x); ierr = PetscDrawLGAddPoint(lg,xx,yy);CHKERRQ(ierr); x += hx; } ierr = PetscDrawAxisSetLabels(axis,"Derivative","","");CHKERRQ(ierr); ierr = PetscDrawLGSetLegend(lg,PETSC_NULL);CHKERRQ(ierr); ierr = PetscDrawLGDraw(lg);CHKERRQ(ierr); ierr = PetscDrawSetPause(draw,pause);CHKERRQ(ierr); ierr = PetscDrawPause(draw);CHKERRQ(ierr); PetscFunctionReturn(0); }
/* FormFunction - Evaluates nonlinear function, F(x). Input Parameters: . ts - the TS context . X - input vector . ptr - optional user-defined context, as set by SNESSetFunction() Output Parameter: . F - function vector */ PetscErrorCode FormFunction(TS ts,PetscReal ftime,Vec X,Vec Xdot,Vec F,void *ptr) { DM da; PetscErrorCode ierr; PetscInt i,Mx,xs,xm; PetscReal hx,sx; Field *x,*xdot,*f; Vec localX,localXdot; UserCtx *ctx = (UserCtx*)ptr; PetscFunctionBegin; ierr = TSGetDM(ts,&da);CHKERRQ(ierr); ierr = DMGetLocalVector(da,&localX);CHKERRQ(ierr); ierr = DMGetLocalVector(da,&localXdot);CHKERRQ(ierr); ierr = DMDAGetInfo(da,PETSC_IGNORE,&Mx,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE, PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE); hx = 1.0/(PetscReal)Mx; sx = 1.0/(hx*hx); /* Scatter ghost points to local vector,using the 2-step process DMGlobalToLocalBegin(),DMGlobalToLocalEnd(). By placing code between these two statements, computations can be done while messages are in transition. */ ierr = DMGlobalToLocalBegin(da,X,INSERT_VALUES,localX);CHKERRQ(ierr); ierr = DMGlobalToLocalEnd(da,X,INSERT_VALUES,localX);CHKERRQ(ierr); ierr = DMGlobalToLocalBegin(da,Xdot,INSERT_VALUES,localXdot);CHKERRQ(ierr); ierr = DMGlobalToLocalEnd(da,Xdot,INSERT_VALUES,localXdot);CHKERRQ(ierr); /* Get pointers to vector data */ ierr = DMDAVecGetArrayRead(da,localX,&x);CHKERRQ(ierr); ierr = DMDAVecGetArrayRead(da,localXdot,&xdot);CHKERRQ(ierr); ierr = DMDAVecGetArray(da,F,&f);CHKERRQ(ierr); /* Get local grid boundaries */ ierr = DMDAGetCorners(da,&xs,NULL,NULL,&xm,NULL,NULL);CHKERRQ(ierr); /* Compute function over the locally owned part of the grid */ for (i=xs; i<xs+xm; i++) { f[i].w = x[i].w + ctx->kappa*(x[i-1].u + x[i+1].u - 2.0*x[i].u)*sx; if (ctx->cahnhillard) { switch (ctx->energy) { case 1: /* double well */ f[i].w += -x[i].u*x[i].u*x[i].u + x[i].u; break; case 2: /* double obstacle */ f[i].w += x[i].u; break; case 3: /* logarithmic */ if (PetscRealPart(x[i].u) < -1.0 + 2.0*ctx->tol) f[i].w += .5*ctx->theta*(-PetscLogReal(ctx->tol) + PetscLogScalar((1.0-x[i].u)/2.0)) + ctx->theta_c*x[i].u; else if (PetscRealPart(x[i].u) > 1.0 - 2.0*ctx->tol) f[i].w += .5*ctx->theta*(-PetscLogScalar((1.0+x[i].u)/2.0) + PetscLogReal(ctx->tol)) + ctx->theta_c*x[i].u; else f[i].w += .5*ctx->theta*(-PetscLogScalar((1.0+x[i].u)/2.0) + PetscLogScalar((1.0-x[i].u)/2.0)) + ctx->theta_c*x[i].u; break; } } f[i].u = xdot[i].u - (x[i-1].w + x[i+1].w - 2.0*x[i].w)*sx; } /* Restore vectors */ ierr = DMDAVecRestoreArrayRead(da,localXdot,&xdot);CHKERRQ(ierr); ierr = DMDAVecRestoreArrayRead(da,localX,&x);CHKERRQ(ierr); ierr = DMDAVecRestoreArray(da,F,&f);CHKERRQ(ierr); ierr = DMRestoreLocalVector(da,&localX);CHKERRQ(ierr); ierr = DMRestoreLocalVector(da,&localXdot);CHKERRQ(ierr); PetscFunctionReturn(0); }