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

  4:  #include <petscsys.h>
  5:  #include <petscdraw.h>

  7: int main(int argc,char **argv)
  8: {
  9:   PetscDraw      draw;
 10:   PetscDrawHG    hist;
 11:   PetscDrawAxis  axis;
 13:   int            n     = 20,i,x = 0,y = 0,width = 400,height = 300,bins = 8;
 14:   PetscInt       w     = 400,h = 300,nn = 20,b = 8,c = PETSC_DRAW_GREEN;
 15:   int            color = PETSC_DRAW_GREEN;
 16:   const char     *xlabel,*ylabel,*toplabel;
 17:   PetscReal      xd;
 18:   PetscBool      flg;

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

 22:   PetscInitialize(&argc,&argv,NULL,help);
 23:   PetscOptionsGetInt(NULL,NULL,"-width",&w,NULL);
 24:   PetscOptionsGetInt(NULL,NULL,"-height",&h,NULL);
 25:   PetscOptionsGetInt(NULL,NULL,"-n",&nn,NULL);
 26:   PetscOptionsGetInt(NULL,NULL,"-bins",&b,NULL);
 27:   PetscOptionsGetInt(NULL,NULL,"-color",&c,NULL);
 28:   PetscOptionsHasName(NULL,NULL,"-nolabels",&flg);
 29:   width = (int) w; height = (int)h; n = (int)nn; bins = (int) b; color = (int) c;
 30:   if (flg) { xlabel = NULL; ylabel = NULL; toplabel = NULL; }

 32:   PetscDrawCreate(PETSC_COMM_WORLD,0,"Title",x,y,width,height,&draw);
 33:   PetscDrawSetFromOptions(draw);
 34:   PetscDrawHGCreate(draw,bins,&hist);
 35:   PetscDrawHGSetColor(hist,color);
 36:   PetscDrawHGGetAxis(hist,&axis);
 37:   PetscDrawAxisSetColors(axis,PETSC_DRAW_BLACK,PETSC_DRAW_RED,PETSC_DRAW_BLUE);
 38:   PetscDrawAxisSetLabels(axis,toplabel,xlabel,ylabel);
 39:   /*PetscDrawHGSetFromOptions(hist);*/

 41:   for (i=0; i<n; i++) {
 42:     xd   = (PetscReal)(i - 5);
 43:     PetscDrawHGAddValue(hist,xd*xd);
 44:   }
 45:   PetscDrawHGDraw(hist);
 46:   PetscDrawHGSave(hist);

 48:   PetscDrawHGDestroy(&hist);
 49:   PetscDrawDestroy(&draw);
 50:   PetscFinalize();
 51:   return ierr;
 52: }



 56: /*TEST

 58:    build:
 59:      requires: x

 61:    test:
 62:      output_file: output/ex1_1.out

 64: TEST*/