Updated gini calculation

Author: mGalarnyk

.DS_Store

@@ -2,7 +2,7 @@
  "cells": [
   {
    "cell_type": "code",
-   "execution_count": 70,
+   "execution_count": 1,
    "metadata": {
     "collapsed": false
    },
@@ -13,7 +13,7 @@
        "'%.3f'"
       ]
      },
-     "execution_count": 70,
+     "execution_count": 1,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -39,7 +39,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 71,
+   "execution_count": 2,
    "metadata": {
     "collapsed": true
    },
@@ -152,7 +152,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 72,
+   "execution_count": 3,
    "metadata": {
     "collapsed": false
    },
@@ -164,7 +164,7 @@
        "<IPython.core.display.Image object>"
       ]
      },
-     "execution_count": 72,
+     "execution_count": 3,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -192,12 +192,12 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "#### Information for Parent"
+    "## Gini for Parent"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 73,
+   "execution_count": 4,
    "metadata": {
     "collapsed": false
    },
@@ -208,7 +208,7 @@
        "0.665"
       ]
      },
-     "execution_count": 73,
+     "execution_count": 4,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -221,12 +221,12 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "#### Information for Child Node (left)"
+    "## Gini for Child Node (left)"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 74,
+   "execution_count": 5,
    "metadata": {
     "collapsed": false
    },
@@ -237,7 +237,7 @@
        "0.000"
       ]
      },
-     "execution_count": 74,
+     "execution_count": 5,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -250,12 +250,12 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "#### Information for Child Node (right)"
+    "## Gini for Child Node (right)"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 75,
+   "execution_count": 6,
    "metadata": {
     "collapsed": false
    },
@@ -266,7 +266,7 @@
        "0.497"
       ]
      },
-     "execution_count": 75,
+     "execution_count": 6,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -279,12 +279,12 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "#### Information Gain (Gini Criterion) "
+    "## Information Gain"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 76,
+   "execution_count": 7,
    "metadata": {
     "collapsed": false
    },
@@ -295,7 +295,7 @@
        "0.168"
       ]
      },
-     "execution_count": 76,
+     "execution_count": 7,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -320,7 +320,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 77,
+   "execution_count": 8,
    "metadata": {
     "collapsed": false
    },
@@ -332,7 +332,7 @@
        "<IPython.core.display.Image object>"
       ]
      },
-     "execution_count": 77,
+     "execution_count": 8,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -360,12 +360,12 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "#### Information for Parent"
+    "## Entropy for Parent"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 78,
+   "execution_count": 18,
    "metadata": {
     "collapsed": false
    },
@@ -376,25 +376,26 @@
        "1.581711119299905"
       ]
      },
-     "execution_count": 78,
+     "execution_count": 18,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "-1*( ((38.0 / 112)* np.log2(38.0/112)) + ((40.0 / 112)* np.log2(40.0/112)) + ((34.0 / 112)* np.log2(34.0/112)) )"
+    "-1*( ((38.0/112)*np.log2(38.0/112))+((40.0/112)*np.log2(40.0/112))\\\n",
+    "    +((34.0/112)*np.log2(34.0/112)) )"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "#### Information for Child Node (left)"
+    "## Entropy for Child Node (left)"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 79,
+   "execution_count": 19,
    "metadata": {
     "collapsed": false
    },
@@ -405,25 +406,25 @@
        "-0.0"
       ]
      },
-     "execution_count": 79,
+     "execution_count": 19,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "-1*(((38.0 / 38.0)* np.log2(38.0/38.0)))"
+    "-1*( ((38.0/38)* np.log2(38.0/38)) )"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "#### Information for Child Node (right)"
+    "## Entropy for Child Node (right)"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 80,
+   "execution_count": 22,
    "metadata": {
     "collapsed": false
    },
@@ -434,25 +435,25 @@
        "0.9952525494396791"
       ]
      },
-     "execution_count": 80,
+     "execution_count": 22,
      "metadata": {},
      "output_type": "execute_result"
     }
    ],
    "source": [
-    "-1*( ((40.0 / 74.0)* np.log2(40.0/74.0)) + ((34.0 / 74.0)* np.log2(34.0/74.0)) )"
+    "-1*( ((40.0/74)* np.log2(40.0/74)) + ((34.0/74)* np.log2(34.0/74)) )"
    ]
   },
   {
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "#### Information Gain"
+    "## Information Gain"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": 81,
+   "execution_count": 23,
    "metadata": {
     "collapsed": false
    },
@@ -463,7 +464,7 @@
        "0.587"
       ]
      },
-     "execution_count": 81,
+     "execution_count": 23,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -476,7 +477,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Bad Split (for blog purposes)\n",
+    "# Bad Split (for blog purposes. Ignore this as it is gini not entropy)\n",
     "petal length <= 3.6 "
    ]
   },