1. size(500,500);
2. background(255);
3.  
4.  //int c = 255;
5.  //int o = 0;
6.  
7.  //grid size change
8. int g =50;
9.  //grid
10.  int h=0;
11.  int i=0;
12.  for ( int a = 0; a<= g; a++){
13.    for ( int b = 0; b<= g; b++){
14.      rect( h,i,width/g,height/g);
15.      h= h+width/g;
16.    }
17.    i=i+height/g;
18.    h=0;
19.  }
20.  
21. stroke(0);
22. strokeWeight(3);
23. line(width*0.5,0,width*0.5,height*1);
24. line(0,height*0.5,width*1,height*0.5);
25.  
26. for (float x = 0; x<height; x = x+(width*0.05)) {
27.      line(width*0.49,x,width*0.51,x);
28.      for ( float y = 0; y<width; y = y+(height*0.05)){
29.         line(y,height*0.49,y,height*0.51);
30.      }
31. }
32. float p=width*0.5;
33. float q=height*0.5;
34. stroke(0,0,255);
35. strokeWeight(width*0.016);
36. point(p,q);
37.  
38. fill(0,0,255);
39. triangle(width*0.5,height*0.01,width*0.49,height*0.02,width*0.51,height*0.02);
40. triangle(width*0.5,height*0.984,width*0.49,height*0.974,width*0.51,height*0.974);
41. triangle(width*0.01,height*0.5,width*0.026,height*0.49,width*0.026,height*0.51);
42. triangle(width*0.99,height*0.5,width*0.964,height*0.49,width*0.964,height*0.51);
43.  
44.  
45. fill(255,0,0);
46. text("0",width*0.516,height*0.53);
47. float f =height*0.45;
48.  for( int u=1; u<=10; u=u+1){
49.    text(u,width*0.472,f);
50.    f = f-(height*0.05);
51.  }
52.   f = height*0.55;
53.  for( int u=-1; u>=-9; u=u-1){
54.    text(u,width*0.462,f);
55.    f = f+(height*0.05);
56.  }
57.  f = width*0.432;
58.  for( int u=-1; u>=-9; u=u-1){
59.    text(u,f,height*0.48);
60.    f = f-(width*0.05);
61.  }
62.  f = width*0.54;
63.  for( int u=1; u<=9; u=u+1){
64.    text(u,f,height*0.48);
65.    f = f+(width*0.05);
66.  }
67. save("Activity12.png");