Coin Flipping Example

xholonWorkbook.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--Xholon Workbook http://www.primordion.com/Xholon/wb/ (C) Ken Webb Sun Oct 27 2013 06:16:36 GMT-0400 (EDT)-->
<XholonWorkbook>
 
<Notes><![CDATA[
Khan Academy
------------
Title: Coin Flipping Example
Description: u08_l4_t1_we3 Coin Flipping Example
Url: http://www.khanacademy.org/video/coin-flipping-example
InternalName: coin-flipping-example
YoutubeId: 3UlE8gyKbkU
Keywords: u08_l4_t1_we3, Coin, Flipping, Example
 
params::
  param_shouldInsertBehaviors=true
 
My Notes
--------
 
Updated Oct 27 2013, with equivalent behaviors for Xholon GWT.
 
Find the probablity of getting exactly two "heads" when flipping three coins.
 
There are 8 possible outcomes::
  HHH   THH
  HHT   THT
  HTH   TTH
  HTT   TTT
  
  this is the sample space
 
Probability of exactly 2 heads::
  there are 3 outcomes with exacly 2 heads - HHT HTH THH
  P(Exactly 2 "H") = outcomes with 2 heads / possible outcomes = 3 / 8
    where P means "probability"
 
]]></Notes>
 
<script implName="lang:python:inline:"><![CDATA[
 
]]></script>
 
<script implName="lang:javascript:inline:"><![CDATA[
 
]]></script>
 
<_-.XholonClass>
 
  <!-- domain objects -->
  <PhysicalSystem/>
  <Coin/>
  <Coins/>
  <Outcomes> <!-- outcomes are the heads and tails that result from flipping coins (ex: HTH) -->
    <TotalOutcomes/> <!-- a count of the total number of outcomes (ex: 8) -->
    <OutcomesWithTwoHeads/> <!-- a count of the number of outcomes with exaclty two heads (ex: 3) -->
  </Outcomes>
  
</_-.XholonClass>
 
<xholonClassDetails>
  <Coins>
    <port name="totalOutcomes" connector="#xpointer(../TotalOutcomes)"/>
    <port name="outcomesWithTwoHeads" connector="#xpointer(../OutcomesWithTwoHeads)"/>
  </Coins>
</xholonClassDetails>
 
<PhysicalSystem>
  <Coins>
    <Coin multiplicity="3"/>
  </Coins>
  <OutcomesWithTwoHeads>0</OutcomesWithTwoHeads>
  <TotalOutcomes>0</TotalOutcomes>
</PhysicalSystem>
 
<Blockbehavior implName="lang:python:inline:"><![CDATA[
 
]]></Blockbehavior>
 
<Blockbehavior implName="lang:javascript:inline:"><![CDATA[
 
]]></Blockbehavior>
 
<Coinbehavior implName="lang:webEditionjs:inline:"><![CDATA[
  var coinFlip = Math.random() * 2;
  if (coinFlip < 1.0) {
    print('H');
    this.parent().attr('val', 'H');
  }
  else {
    print('T');
    this.parent().attr('val', 'T');
  }
]]></Coinbehavior>
 
<Coinsbehavior implName="lang:webEditionjs:inline:"><![CDATA[
  this.bindPorts(this.parent());
  this.totalOutcomes.incVal(1);
  var coins = this.siblings('.Coin');
  var heads = coins.filter('[val="H"]');
  if (heads.length == 2) {
    this.outcomesWithTwoHeads.incVal(1);
  }
  var probability = this.outcomesWithTwoHeads.attr('val') / this.totalOutcomes.attr('val');
  println(" " + probability);
  var svg = $($('div#mySVGDiv > object')[0].contentDocument.getElementsByTagNameNS(svgns, 'svg')[0]);
  var rectSVG = svg.children('g').children('g').children('rect');
  rectSVG.attr('height', probability * 80);
  rectSVG.attr('y', 80 - (probability * 80));
]]></Coinsbehavior>
 
<Coinbehavior implName="org.primordion.xholon.base.Behavior_gwtjs"><![CDATA[
var beh = {
  act: function() {
    var coin = this.cnode.parent();  
    var coinFlip = Math.random() * 2;
    if (coinFlip < 1.0) {
      coin.print('H');
      coin.val(1); // 'H'
    }
    else {
      coin.print('T');
      coin.val(0); // 'T'
    }
  }
}
]]></Coinbehavior>
 
<Coinsbehavior implName="org.primordion.xholon.base.Behavior_gwtjs"><![CDATA[
var coins, rectSVG;
var beh = {
  postConfigure: function() {
    coins = this.cnode.parent();
  },
  
  act: function() {
    coins.totalOutcomes.inc(1);
    var hcount = 0;
    var coin = coins.first();
    while (coin != null) {
      if (coin.val()) {
        hcount++;
      }
      coin = coin.next();
    }
    if (hcount == 2) {
      coins.outcomesWithTwoHeads.inc(1);
    }
    var probability = coins.outcomesWithTwoHeads.val() / coins.totalOutcomes.val();
    coins.println(" " + probability);
    
    // SVG
    if (!rectSVG) {
      // SVG setup
      var svg = $doc.getElementById("xhsvg").firstElementChild.firstElementChild;
      rectSVG = svg.getElementById("PhysicalSystem/OutcomesWithTwoHeads");
    }
    rectSVG.setAttributeNS(null, 'height', probability * 80);
    rectSVG.setAttributeNS(null, 'y', 80 - (probability * 80));
  }
}
]]></Coinsbehavior>
 
<Blockbehavior implName="lang:bsh:inline:"><![CDATA[
 
]]></Blockbehavior>
 
<Blockbehavior implName="lang:jruby:inline:"><![CDATA[
 
]]></Blockbehavior>
 
<Blockbehavior implName="lang:groovy:inline:"><![CDATA[
 
]]></Blockbehavior>
 
<SvgClient><Attribute_String roleName="svgUri"><![CDATA[data:image/svg+xml,
<svg width="100" height="80" xmlns="http://www.w3.org/2000/svg">
  <g>
    <title>TotalOutcomes</title>
    <rect id="PhysicalSystem/TotalOutcomes" fill="#98FB98" height="80" width="50" x="25" y="0"/>
    <g>
      <title>OutcomesWithTwoHeads</title>
      <rect id="PhysicalSystem/OutcomesWithTwoHeads" fill="#6AB06A" height="0.0" width="50" x="25" y="37.5"/>
      <line x1="20" y1="50.0" x2="80" y2="50.0" style="stroke:rgb(0,0,255);stroke-width:1"/>
    </g>
  </g>
</svg>
]]></Attribute_String><Attribute_String roleName="setup">${MODELNAME_DEFAULT},${SVGURI_DEFAULT}</Attribute_String></SvgClient>
 
</XholonWorkbook>