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Making a circle out of . (periods) [closed]

Solutons:


Here’s the maths and even an example program in C:

http://pixwiki.bafsoft.com/mags/5/articles/circle/sincos.htm (link no longer exists).

And position: absolute, left and top will let you draw:

http://www.w3.org/TR/CSS2/visuren.html#choose-position

Any further questions?

I know you asked for just the circumference, but it seemed easier to do a filled circle.

<html>
  <head>
    <script type="text/javascript" src="http://www.google.com/jsapi"></script>
    <script type="text/javascript">
      google.load("jquery", "1");
    </script>
  </head>
  <body>
    <script type="text/javascript">
      function drawCircle(left, top, radius) {
        var pre = $("<pre/>").css({position: "absolute", top: top, left: left}).appendTo($("body"));
        var testSpan = $("<span> </span>").appendTo(pre);
        var cellWidth = testSpan.width();
        var cellHeight = testSpan.height();
        testSpan.remove();
        var diameter = 2 * radius;
        var dotArray = [];
        for (var row = 0; row <= diameter / cellHeight; row++) {
          for (var column = 0; column <= diameter / cellWidth; column++) {
            var cellDY = Math.abs(row * cellHeight - radius) - cellHeight / 2;
            var cellDX = Math.abs(column * cellWidth - radius) - cellWidth / 2;
            var distance = Math.pow(cellDY, 2) + Math.pow(cellDX, 2);
            if (distance < Math.pow(radius, 2)) {
              dotArray.push(".");
            } else {
              dotArray.push(" ");
            }
          }
          dotArray.push("<br/>");
        }
        pre.html(dotArray.join(""));
      }
      drawCircle(20, 20, 200);
  </script> 
  </body>
</html>

Yes, it is possible. Put the below code into an html file to see it in action.

A quick run through: The code generates an array of dots and spaces. It chooses to make a dot based on if the distance from the current x, y position to the center of the circle is less than or equal to the length of the radius via the distance formula ( http://www.purplemath.com/modules/distform.htm ).

<div id= "mydiv" style="font-family: monospace"> </div> 

<script type="text/javascript"> 
    var x = 2; //starting x,y position of circle
    var y = 5; 
    var rad = 4; //radius of circle

    var width = 10; //width and height of display
    var height = 10;

    var dotArray = "";

    for (var i=0;i<width;i++){
        for (var j=0;j<height;j++){
            if (Math.sqrt( Math.pow(i-y, 2) + Math.pow(j-x, 2)) <= rad){
                dotArray += (".");
            } else {
                dotArray += ("&nbsp;");
            }
        }
        dotArray += "<br >";
    }

document.getElementById('mydiv').innerHTML = dotArray;
</script> 

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