xref: /petsc/src/ts/tutorials/phasefield/potentials.c (revision 030f984af8d8bb4c203755d35bded3c05b3d83ce)
1 
2 static char help[] = "Plots the various potentials used in the examples.\n";
3 
4 #include <petscdmda.h>
5 #include <petscts.h>
6 #include <petscdraw.h>
7 
8 int main(int argc,char **argv)
9 {
10   PetscDrawLG               lg;
11   PetscErrorCode            ierr;
12   PetscInt                  Mx = 100,i;
13   PetscReal                 x,hx = .1/Mx,pause,xx[3],yy[3];
14   PetscDraw                 draw;
15   const char *const         legend[] = {"(1 - u^2)^2","1 - u^2","-(1 - u)log(1 - u)"};
16   PetscDrawAxis             axis;
17   PetscDrawViewPorts        *ports;
18 
19   PetscFunctionBegin;
20   ierr = PetscInitialize(&argc,&argv,0,help);if (ierr) return ierr;
21   ierr = PetscViewerDrawResize(PETSC_VIEWER_DRAW_(PETSC_COMM_WORLD),1200,800);CHKERRQ(ierr);
22   ierr = PetscViewerDrawGetDrawLG(PETSC_VIEWER_DRAW_(PETSC_COMM_WORLD),0,&lg);CHKERRQ(ierr);
23   ierr = PetscDrawLGGetDraw(lg,&draw);CHKERRQ(ierr);
24   ierr = PetscDrawCheckResizedWindow(draw);CHKERRQ(ierr);
25   ierr = PetscDrawViewPortsCreateRect(draw,1,2,&ports);CHKERRQ(ierr);
26   ierr = PetscDrawLGGetAxis(lg,&axis);CHKERRQ(ierr);
27   ierr = PetscDrawLGReset(lg);CHKERRQ(ierr);
28 
29   /*
30       Plot the  energies
31   */
32   ierr = PetscDrawLGSetDimension(lg,3);CHKERRQ(ierr);
33   ierr = PetscDrawViewPortsSet(ports,1);CHKERRQ(ierr);
34   x    = .9;
35   for (i=0; i<Mx; i++) {
36     xx[0] = xx[1] = xx[2] = x;
37     yy[0] = (1.-x*x)*(1. - x*x);
38     yy[1] = (1. - x*x);
39     yy[2] = -(1.-x)*PetscLogReal(1.-x);
40     ierr  = PetscDrawLGAddPoint(lg,xx,yy);CHKERRQ(ierr);
41     x    += hx;
42   }
43   ierr = PetscDrawGetPause(draw,&pause);CHKERRQ(ierr);
44   ierr = PetscDrawSetPause(draw,0.0);CHKERRQ(ierr);
45   ierr = PetscDrawAxisSetLabels(axis,"Energy","","");CHKERRQ(ierr);
46   ierr = PetscDrawLGSetLegend(lg,legend);CHKERRQ(ierr);
47   ierr = PetscDrawLGDraw(lg);CHKERRQ(ierr);
48 
49   /*
50       Plot the  forces
51   */
52   ierr = PetscDrawViewPortsSet(ports,0);CHKERRQ(ierr);
53   ierr = PetscDrawLGReset(lg);CHKERRQ(ierr);
54   x    = .9;
55   for (i=0; i<Mx; i++) {
56     xx[0] = xx[1] = xx[2] = x;
57     yy[0] = x*x*x - x;
58     yy[1] = -x;
59     yy[2] = 1.0 + PetscLogReal(1. - x);
60     ierr  = PetscDrawLGAddPoint(lg,xx,yy);CHKERRQ(ierr);
61     x    += hx;
62   }
63   ierr = PetscDrawAxisSetLabels(axis,"Derivative","","");CHKERRQ(ierr);
64   ierr = PetscDrawLGSetLegend(lg,NULL);CHKERRQ(ierr);
65   ierr = PetscDrawLGDraw(lg);CHKERRQ(ierr);
66 
67   ierr = PetscDrawSetPause(draw,pause);CHKERRQ(ierr);
68   ierr = PetscDrawPause(draw);CHKERRQ(ierr);
69   ierr = PetscDrawViewPortsDestroy(ports);CHKERRQ(ierr);
70   ierr = PetscFinalize();
71   return ierr;
72 }
73 
74 /*TEST
75 
76    test:
77      requires: x
78 
79 TEST*/
80