Actual source code: ex9.c

  2: static char help[] = "Makes a simple histogram.\n";

 4:  #include petscsys.h

  8: int main(int argc,char **argv)
  9: {
 10:   PetscDraw       draw;
 11:   PetscDrawHG     hist;
 12:   PetscDrawAxis   axis;
 14:   int             n = 20,i,x = 0,y = 0,width = 300,height = 300,bins = 8;
 15:   PetscInt        w = 300,h = 300,nn = 20,b = 8,c = PETSC_DRAW_GREEN;
 16:   int             color = PETSC_DRAW_GREEN;
 17:   const char      *xlabel,*ylabel,*toplabel;
 18:   PetscReal       xd;
 19:   PetscTruth      flg;

 21:   xlabel = "X-axis Label";toplabel = "Top Label";ylabel = "Y-axis Label";

 23:   PetscInitialize(&argc,&argv,(char*)0,help);
 24:   PetscOptionsGetInt(PETSC_NULL,"-width",&w,PETSC_NULL);
 25:   PetscOptionsGetInt(PETSC_NULL,"-height",&h,PETSC_NULL);
 26:   PetscOptionsGetInt(PETSC_NULL,"-n",&nn,PETSC_NULL);
 27:   PetscOptionsGetInt(PETSC_NULL,"-bins",&b,PETSC_NULL);
 28:   PetscOptionsGetInt(PETSC_NULL,"-color",&c,PETSC_NULL);
 29:   PetscOptionsHasName(PETSC_NULL,"-nolabels",&flg);
 30:   width = (int) w; height = (int)h; n = (int)nn; bins = (int) b; color = (int) c;
 31:   if (flg) {
 32:     xlabel = (char *)0; toplabel = (char *)0;
 33:   }
 34:   /* PetscDrawOpenX(PETSC_COMM_SELF,0,"Title",x,y,width,height,&draw);*/
 35:   PetscDrawCreate(PETSC_COMM_SELF,0,"Title",x,y,width,height,&draw);
 36:   PetscDrawSetType(draw,PETSC_DRAW_X);
 37:   PetscDrawHGCreate(draw,bins,&hist);
 38:   PetscDrawHGGetAxis(hist,&axis);
 39:   PetscDrawAxisSetColors(axis,PETSC_DRAW_BLACK,PETSC_DRAW_RED,PETSC_DRAW_BLUE);
 40:   PetscDrawAxisSetLabels(axis,toplabel,xlabel,ylabel);

 42:   for (i=0; i<n ; i++) {
 43:     xd = (PetscReal)(i - 5);
 44:     PetscDrawHGAddValue(hist,xd*xd);
 45:   }
 46:   PetscDrawHGSetColor(hist,color);
 47:   PetscDrawHGDraw(hist);
 48:   PetscDrawFlush(draw);

 50:   PetscDrawHGDestroy(hist);
 51:   PetscDrawDestroy(draw);
 52:   PetscFinalize();
 53:   return 0;
 54: }
 55: