int main(int argc,char **argv)
{
PetscDraw draw;
PetscDrawLG lg;
PetscDrawAxis axis;
PetscInt n = 15,i,x = 0,y = 0,width = 400,height = 300,nports = 1;
PetscBool useports,flg;
const char *xlabel,*ylabel,*toplabel,*legend;
PetscReal xd,yd;
PetscDrawViewPorts *ports = NULL;
PetscErrorCode ierr;
toplabel = "Top Label"; xlabel = "X-axis Label"; ylabel = "Y-axis Label"; legend = "Legend";
ierr = PetscInitialize(&argc,&argv,NULL,help);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,NULL,"-x",&x,NULL);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,NULL,"-y",&y,NULL);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,NULL,"-width",&width,NULL);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,NULL,"-height",&height,NULL);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,NULL,"-nports",&nports,&useports);CHKERRQ(ierr);
ierr = PetscOptionsHasName(NULL,NULL,"-nolegend",&flg);CHKERRQ(ierr);
if (flg) legend = NULL;
ierr = PetscOptionsHasName(NULL,NULL,"-notoplabel",&flg);CHKERRQ(ierr);
if (flg) toplabel = NULL;
ierr = PetscOptionsHasName(NULL,NULL,"-noxlabel",&flg);CHKERRQ(ierr);
if (flg) xlabel = NULL;
ierr = PetscOptionsHasName(NULL,NULL,"-noylabel",&flg);CHKERRQ(ierr);
if (flg) ylabel = NULL;
ierr = PetscOptionsHasName(NULL,NULL,"-nolabels",&flg);CHKERRQ(ierr);
if (flg) {toplabel = NULL; xlabel = NULL; ylabel = NULL;}
ierr = PetscDrawCreate(PETSC_COMM_WORLD,0,"Title",x,y,width,height,&draw);CHKERRQ(ierr);
ierr = PetscDrawSetFromOptions(draw);CHKERRQ(ierr);
if (useports) {
ierr = PetscDrawViewPortsCreate(draw,nports,&ports);CHKERRQ(ierr);
ierr = PetscDrawViewPortsSet(ports,0);CHKERRQ(ierr);
}
ierr = PetscDrawLGCreate(draw,1,&lg);CHKERRQ(ierr);
ierr = PetscDrawLGSetUseMarkers(lg,PETSC_TRUE);CHKERRQ(ierr);
ierr = PetscDrawLGGetAxis(lg,&axis);CHKERRQ(ierr);
ierr = PetscDrawAxisSetColors(axis,PETSC_DRAW_BLACK,PETSC_DRAW_RED,PETSC_DRAW_BLUE);CHKERRQ(ierr);
ierr = PetscDrawAxisSetLabels(axis,toplabel,xlabel,ylabel);CHKERRQ(ierr);
ierr = PetscDrawLGSetLegend(lg,&legend);CHKERRQ(ierr);
ierr = PetscDrawLGSetFromOptions(lg);CHKERRQ(ierr);
for (i=0; i<=n; i++) {
xd = (PetscReal)(i - 5); yd = xd*xd;
ierr = PetscDrawLGAddPoint(lg,&xd,&yd);CHKERRQ(ierr);
}
ierr = PetscDrawLGDraw(lg);CHKERRQ(ierr);
ierr = PetscDrawLGSave(lg);CHKERRQ(ierr);
ierr = PetscDrawViewPortsDestroy(ports);CHKERRQ(ierr);
ierr = PetscDrawLGDestroy(&lg);CHKERRQ(ierr);
ierr = PetscDrawDestroy(&draw);CHKERRQ(ierr);
ierr = PetscFinalize();
return ierr;
}
/*@
PetscDrawLGSetFromOptions - Sets options related to the PetscDrawLG
Collective on PetscDrawLG
Options Database:
Level: intermediate
Concepts: line graph^creating
.seealso: PetscDrawLGDestroy(), PetscDrawLGCreate()
@*/
PetscErrorCode PetscDrawLGSetFromOptions(PetscDrawLG lg)
{
PetscErrorCode ierr;
PetscBool usemarkers,set;
PetscDrawMarkerType markertype;
PetscFunctionBegin;
PetscValidHeaderSpecific(lg,PETSC_DRAWLG_CLASSID,1);
ierr = PetscDrawGetMarkerType(lg->win,&markertype);CHKERRQ(ierr);
ierr = PetscOptionsGetEnum(((PetscObject)lg)->options,((PetscObject)lg)->prefix,"-lg_marker_type",PetscDrawMarkerTypes,(PetscEnum*)&markertype,&set);CHKERRQ(ierr);
if (set) {
ierr = PetscDrawLGSetUseMarkers(lg,PETSC_TRUE);CHKERRQ(ierr);
ierr = PetscDrawSetMarkerType(lg->win,markertype);CHKERRQ(ierr);
}
usemarkers = lg->use_markers;
ierr = PetscOptionsGetBool(((PetscObject)lg)->options,((PetscObject)lg)->prefix,"-lg_use_markers",&usemarkers,&set);CHKERRQ(ierr);
if (set) {ierr = PetscDrawLGSetUseMarkers(lg,usemarkers);CHKERRQ(ierr);}
PetscFunctionReturn(0);
}
int main(int argc,char **argv)
{
PetscDraw draw;
PetscDrawLG lg;
PetscDrawAxis axis;
PetscInt n = 20,i,x = 0,y = 0,width = 300,height = 300,nports = 1;
PetscBool flg;
const char *xlabel,*ylabel,*toplabel;
PetscReal xd,yd;
PetscDrawViewPorts *ports;
PetscErrorCode ierr;
xlabel = "X-axis Label";
toplabel = "Top Label";
ylabel = "Y-axis Label";
ierr = PetscInitialize(&argc,&argv,(char*)0,help);
CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,"-width",&width,NULL);
CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,"-height",&height,NULL);
CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,"-n",&n,NULL);
CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,"-nports",&nports,NULL);
CHKERRQ(ierr);
ierr = PetscOptionsHasName(NULL,"-nolabels",&flg);
CHKERRQ(ierr);
if (flg) {
toplabel = NULL;
xlabel = NULL;
ylabel = NULL;
}
ierr = PetscDrawCreate(PETSC_COMM_WORLD,0,"Title",x,y,width,height,&draw);
CHKERRQ(ierr);
ierr = PetscDrawSetFromOptions(draw);
CHKERRQ(ierr);
ierr = PetscDrawViewPortsCreate(draw,nports,&ports);
CHKERRQ(ierr);
ierr = PetscDrawViewPortsSet(ports,0);
CHKERRQ(ierr);
ierr = PetscDrawLGCreate(draw,1,&lg);
CHKERRQ(ierr);
ierr = PetscDrawDestroy(&draw);
CHKERRQ(ierr);
ierr = PetscDrawLGGetAxis(lg,&axis);
CHKERRQ(ierr);
ierr = PetscDrawAxisSetColors(axis,PETSC_DRAW_BLACK,PETSC_DRAW_RED,PETSC_DRAW_BLUE);
CHKERRQ(ierr);
ierr = PetscDrawAxisSetLabels(axis,toplabel,xlabel,ylabel);
CHKERRQ(ierr);
for (i=0; i<n; i++) {
xd = (PetscReal)(i - 5);
yd = xd*xd;
ierr = PetscDrawLGAddPoint(lg,&xd,&yd);
CHKERRQ(ierr);
}
ierr = PetscDrawLGSetUseMarkers(lg,PETSC_TRUE);
CHKERRQ(ierr);
ierr = PetscDrawLGDraw(lg);
CHKERRQ(ierr);
ierr = PetscDrawLGGetDraw(lg,&draw);
CHKERRQ(ierr);
ierr = PetscDrawString(draw,-3.,150.0,PETSC_DRAW_BLUE,"A legend");
CHKERRQ(ierr);
ierr = PetscDrawSynchronizedFlush(draw);
CHKERRQ(ierr);
ierr = PetscDrawLGDestroy(&lg);
CHKERRQ(ierr);
ierr = PetscDrawViewPortsDestroy(ports);
CHKERRQ(ierr);
ierr = PetscFinalize();
return 0;
}
/*
Run with -build_twosided allreduce -pc_type bjacobi -sub_pc_type lu -q 16 -ksp_rtol 1.e-34 (or 1.e-14 for double precision)
-q <q> number of spectral elements to use
-N <N> maximum number of GLL points per element
*/
int main(int argc,char **args)
{
PetscErrorCode ierr;
PetscGLL gll;
PetscInt N = 80,n,q = 8,xs,xn,j,l;
PetscReal **A;
Mat K;
KSP ksp;
PC pc;
Vec x,b;
PetscInt *rows;
PetscReal norm,xc,yc,h;
PetscScalar *f;
PetscDraw draw;
PetscDrawLG lg;
PetscDrawAxis axis;
DM da;
PetscMPIInt rank,size;
ierr = PetscInitialize(&argc,&args,NULL,NULL);if (ierr) return ierr;
ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,NULL,"-N",&N,NULL);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,NULL,"-q",&q,NULL);CHKERRQ(ierr);
ierr = PetscDrawCreate(PETSC_COMM_WORLD,NULL,"Log(Error norm) vs Number of GLL points",0,0,500,500,&draw);CHKERRQ(ierr);
ierr = PetscDrawSetFromOptions(draw);CHKERRQ(ierr);
ierr = PetscDrawLGCreate(draw,1,&lg);CHKERRQ(ierr);
ierr = PetscDrawLGSetUseMarkers(lg,PETSC_TRUE);CHKERRQ(ierr);
ierr = PetscDrawLGGetAxis(lg,&axis);CHKERRQ(ierr);
ierr = PetscDrawAxisSetLabels(axis,NULL,"Number of GLL points","Log(Error Norm)");CHKERRQ(ierr);
for (n=4; n<N; n+=2) {
/*
da contains the information about the parallel layout of the elements
*/
ierr = DMDACreate1d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,q*(n-1)+1,1,1,NULL,&da);CHKERRQ(ierr);
ierr = DMSetFromOptions(da);CHKERRQ(ierr);
ierr = DMSetUp(da);CHKERRQ(ierr);
ierr = DMDAGetInfo(da,NULL,&q,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL);CHKERRQ(ierr);
q = (q-1)/(n-1); /* number of spectral elements */
/*
gll simply contains the GLL node and weight values
*/
ierr = PetscGLLCreate(n,PETSCGLL_VIA_LINEARALGEBRA,&gll);CHKERRQ(ierr);
ierr = DMDASetGLLCoordinates(da,&gll);CHKERRQ(ierr);
/*
Creates the element stiffness matrix for the given gll
*/
ierr = PetscGLLElementLaplacianCreate(&gll,&A);CHKERRQ(ierr);
/*
Scale the element stiffness and weights by the size of the element
*/
h = 2.0/q;
for (j=0; j<n; j++) {
gll.weights[j] *= .5*h;
for (l=0; l<n; l++) {
A[j][l] = 2.*A[j][l]/h;
}
}
/*
Create the global stiffness matrix and add the element stiffness for each local element
*/
ierr = DMCreateMatrix(da,&K);CHKERRQ(ierr);
ierr = MatSetOption(K,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_FALSE);CHKERRQ(ierr);
ierr = DMDAGetCorners(da,&xs,NULL,NULL,&xn,NULL,NULL);CHKERRQ(ierr);
xs = xs/(n-1);
xn = xn/(n-1);
ierr = PetscMalloc1(n,&rows);CHKERRQ(ierr);
/*
loop over local elements
*/
for (j=xs; j<xs+xn; j++) {
for (l=0; l<n; l++) rows[l] = j*(n-1)+l;
ierr = MatSetValues(K,n,rows,n,rows,&A[0][0],ADD_VALUES);CHKERRQ(ierr);
}
ierr = MatAssemblyBegin(K,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = MatAssemblyEnd(K,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = MatCreateVecs(K,&x,&b);CHKERRQ(ierr);
ierr = ComputeRhs(da,&gll,b);CHKERRQ(ierr);
/*
Replace the first and last rows/columns of the matrix with the identity to obtain the zero Dirichlet boundary conditions
*/
rows[0] = 0;
rows[1] = q*(n-1);
ierr = MatZeroRowsColumns(K,2,rows,1.0,x,b);CHKERRQ(ierr);
ierr = PetscFree(rows);CHKERRQ(ierr);
ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);CHKERRQ(ierr);
ierr = KSPSetOperators(ksp,K,K);CHKERRQ(ierr);
ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr);
ierr = PCSetType(pc,PCLU);CHKERRQ(ierr);
ierr = KSPSetFromOptions(ksp);CHKERRQ(ierr);
ierr = KSPSolve(ksp,b,x);CHKERRQ(ierr);
/* compute the error to the continium problem */
ierr = ComputeSolution(da,&gll,b);CHKERRQ(ierr);
ierr = VecAXPY(x,-1.0,b);CHKERRQ(ierr);
/* compute the L^2 norm of the error */
ierr = VecGetArray(x,&f);CHKERRQ(ierr);
ierr = PetscGLLIntegrate(&gll,f,&norm);CHKERRQ(ierr);
ierr = VecRestoreArray(x,&f);CHKERRQ(ierr);
norm = PetscSqrtReal(norm);
ierr = PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD,"L^2 norm of the error %D %g\n",n,(double)norm);CHKERRQ(ierr);
if (n > 10 && norm > 1.e-8) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Slower convergence than expected");
xc = (PetscReal)n;
yc = PetscLog10Real(norm);
ierr = PetscDrawLGAddPoint(lg,&xc,&yc);CHKERRQ(ierr);
ierr = PetscDrawLGDraw(lg);CHKERRQ(ierr);
ierr = VecDestroy(&b);CHKERRQ(ierr);
ierr = VecDestroy(&x);CHKERRQ(ierr);
ierr = KSPDestroy(&ksp);CHKERRQ(ierr);
ierr = MatDestroy(&K);CHKERRQ(ierr);
ierr = PetscGLLElementLaplacianDestroy(&gll,&A);CHKERRQ(ierr);
ierr = PetscGLLDestroy(&gll);CHKERRQ(ierr);
ierr = DMDestroy(&da);CHKERRQ(ierr);
}
ierr = PetscDrawLGDestroy(&lg);CHKERRQ(ierr);
ierr = PetscDrawDestroy(&draw);CHKERRQ(ierr);
ierr = PetscFinalize();
return ierr;
}
