title: How to overwrite a function using a userscript?
body: <p>I want to change parts of the webpage display, is it possible to overwrite a function with a userscript? </p>
  
  <p>Below is the function I would like overwritten (also <a href="https://github.com/marbindrakon/eve-wspace/blob/develop/evewspace/Map/static/js/map_functions.js#L697" rel="nofollow">found Here</a>):</p>
  
  <pre><code>function StartDrawing() {
      if ((typeof (systemsJSON) != "undefined") &amp;&amp; (systemsJSON != null)) {
          var stellarSystemsLength = systemsJSON.length;
          $('#mapDiv').empty();
          if (stellarSystemsLength &gt; 0) {
              InitializeRaphael();
  
              var i = 0;
              for (i = 0; i &lt; stellarSystemsLength; i++){
                  var stellarSystem = systemsJSON[i];
                  DrawSystem(stellarSystem)
              }
          }
      }
  }
  </code></pre>
  
  <p>This would allow me to run my own drawing algorithms.</p>
  
  <p>How do I do this with a userscript in chromium (or Firefox)?</p>