PetscErrorCode VecView_Seq_Draw_LG(Vec xin,PetscViewer v)
{
PetscDraw draw;
PetscBool isnull;
PetscDrawLG lg;
PetscErrorCode ierr;
PetscInt i,c,bs = PetscAbs(xin->map->bs),n = xin->map->n/bs;
const PetscScalar *xv;
PetscReal *xx,*yy;
int colors[] = {PETSC_DRAW_RED};
PetscFunctionBegin;
ierr = PetscViewerDrawGetDraw(v,0,&draw);CHKERRQ(ierr);
ierr = PetscDrawIsNull(draw,&isnull);CHKERRQ(ierr);
if (isnull) PetscFunctionReturn(0);
ierr = PetscMalloc2(n,&xx,n,&yy);CHKERRQ(ierr);
ierr = VecGetArrayRead(xin,&xv);CHKERRQ(ierr);
for (c=0; c<bs; c++) {
ierr = PetscViewerDrawGetDrawLG(v,c,&lg);CHKERRQ(ierr);
ierr = PetscDrawLGReset(lg);CHKERRQ(ierr);
ierr = PetscDrawLGSetDimension(lg,1);CHKERRQ(ierr);
ierr = PetscDrawLGSetColors(lg,colors);CHKERRQ(ierr);
for (i=0; i<n; i++) {
xx[i] = (PetscReal)i;
yy[i] = PetscRealPart(xv[c + i*bs]);
}
ierr = PetscDrawLGAddPoints(lg,n,&xx,&yy);CHKERRQ(ierr);
ierr = PetscDrawLGDraw(lg);CHKERRQ(ierr);
ierr = PetscDrawLGSave(lg);CHKERRQ(ierr);
}
ierr = VecRestoreArrayRead(xin,&xv);CHKERRQ(ierr);
ierr = PetscFree2(xx,yy);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
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;
}
