1: static char help[] = "Plots the various potentials used in the examples.\n";

  3: #include <petscdmda.h>
  4: #include <petscts.h>
  5: #include <petscdraw.h>

  7: int main(int argc, char **argv)
  8: {
  9:   PetscDrawLG         lg;
 10:   PetscInt            Mx = 100, i;
 11:   PetscReal           x, hx = .1 / Mx, pause, xx[3], yy[3];
 12:   PetscDraw           draw;
 13:   const char *const   legend[] = {"(1 - u^2)^2", "1 - u^2", "-(1 - u)log(1 - u)"};
 14:   PetscDrawAxis       axis;
 15:   PetscDrawViewPorts *ports;

 17:   PetscFunctionBegin;
 18:   PetscFunctionBeginUser;
 19:   PetscCall(PetscInitialize(&argc, &argv, 0, help));
 20:   PetscCall(PetscViewerDrawResize(PETSC_VIEWER_DRAW_(PETSC_COMM_WORLD), 1200, 800));
 21:   PetscCall(PetscViewerDrawGetDrawLG(PETSC_VIEWER_DRAW_(PETSC_COMM_WORLD), 0, &lg));
 22:   PetscCall(PetscDrawLGGetDraw(lg, &draw));
 23:   PetscCall(PetscDrawCheckResizedWindow(draw));
 24:   PetscCall(PetscDrawViewPortsCreateRect(draw, 1, 2, &ports));
 25:   PetscCall(PetscDrawLGGetAxis(lg, &axis));
 26:   PetscCall(PetscDrawLGReset(lg));

 28:   /*
 29:       Plot the  energies
 30:   */
 31:   PetscCall(PetscDrawLGSetDimension(lg, 3));
 32:   PetscCall(PetscDrawViewPortsSet(ports, 1));
 33:   x = .9;
 34:   for (i = 0; i < Mx; i++) {
 35:     xx[0] = xx[1] = xx[2] = x;
 36:     yy[0]                 = (1. - x * x) * (1. - x * x);
 37:     yy[1]                 = (1. - x * x);
 38:     yy[2]                 = -(1. - x) * PetscLogReal(1. - x);
 39:     PetscCall(PetscDrawLGAddPoint(lg, xx, yy));
 40:     x += hx;
 41:   }
 42:   PetscCall(PetscDrawGetPause(draw, &pause));
 43:   PetscCall(PetscDrawSetPause(draw, 0.0));
 44:   PetscCall(PetscDrawAxisSetLabels(axis, "Energy", "", ""));
 45:   PetscCall(PetscDrawLGSetLegend(lg, legend));
 46:   PetscCall(PetscDrawLGDraw(lg));

 48:   /*
 49:       Plot the  forces
 50:   */
 51:   PetscCall(PetscDrawViewPortsSet(ports, 0));
 52:   PetscCall(PetscDrawLGReset(lg));
 53:   x = .9;
 54:   for (i = 0; i < Mx; i++) {
 55:     xx[0] = xx[1] = xx[2] = x;
 56:     yy[0]                 = x * x * x - x;
 57:     yy[1]                 = -x;
 58:     yy[2]                 = 1.0 + PetscLogReal(1. - x);
 59:     PetscCall(PetscDrawLGAddPoint(lg, xx, yy));
 60:     x += hx;
 61:   }
 62:   PetscCall(PetscDrawAxisSetLabels(axis, "Derivative", "", ""));
 63:   PetscCall(PetscDrawLGSetLegend(lg, NULL));
 64:   PetscCall(PetscDrawLGDraw(lg));

 66:   PetscCall(PetscDrawSetPause(draw, pause));
 67:   PetscCall(PetscDrawPause(draw));
 68:   PetscCall(PetscDrawViewPortsDestroy(ports));
 69:   PetscCall(PetscFinalize());
 70:   return 0;
 71: }

 73: /*TEST

 75:    test:
 76:      requires: x

 78: TEST*/