Changes during first Python class

Author: dham

notebook/Python-1.ipynb

@@ -73,24 +73,21 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 2,
+   "execution_count": 3,
    "metadata": {
     "collapsed": false
    },
    "outputs": [
     {
-     "ename": "TypeError",
-     "evalue": "unsupported operand type(s) for ^: 'float' and 'int'",
-     "output_type": "error",
-     "traceback": [
-      "\u001b[0;31m---------------------------------------------------------------------------\u001b[0m\n\u001b[0;31mTypeError\u001b[0m                                 Traceback (most recent call last)",
-      "\u001b[0;32m<ipython-input-2-2cffe887fbc6>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m()\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0;32mprint\u001b[0m \u001b[0;36m5\u001b[0m\u001b[0;34m*\u001b[0m\u001b[0;36m0.6\u001b[0m \u001b[0;34m-\u001b[0m \u001b[0;36m0.5\u001b[0m\u001b[0;34m*\u001b[0m\u001b[0;36m9.81\u001b[0m\u001b[0;34m*\u001b[0m\u001b[0;36m0.6\u001b[0m\u001b[0;34m^\u001b[0m\u001b[0;36m2\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
-      "\u001b[0;31mTypeError\u001b[0m: unsupported operand type(s) for ^: 'float' and 'int'"
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "1.2342\n"
      ]
     }
    ],
    "source": [
-    "print 5*0.6 - 0.5*9.81*0.6^2"
+    "print 5*0.6 - 0.5*9.81*0.6**2"
    ]
   },
   {
@@ -139,7 +136,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 4,
+   "execution_count": 7,
    "metadata": {
     "collapsed": false
    },
@@ -160,6 +157,29 @@
     "print y"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "<type 'int'>\n",
+      "<type 'float'>\n"
+     ]
+    }
+   ],
+   "source": [
+    "a=2\n",
+    "print type(a)\n",
+    "a=2.5\n",
+    "print type(a)"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -179,7 +199,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 5,
+   "execution_count": 10,
    "metadata": {
     "collapsed": false
    },
@@ -250,12 +270,24 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 14,
    "metadata": {
     "collapsed": false
    },
-   "outputs": [],
-   "source": []
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "0.5\n"
+     ]
+    }
+   ],
+   "source": [
+    "length = 666\n",
+    "from __future__ import division\n",
+    "print 1/2"
+   ]
   },
   {
    "cell_type": "markdown",
@@ -267,7 +299,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": 7,
+   "execution_count": 16,
    "metadata": {
     "collapsed": false
    },
@@ -334,12 +366,23 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 18,
    "metadata": {
     "collapsed": false
    },
-   "outputs": [],
-   "source": []
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "3.142\n"
+     ]
+    }
+   ],
+   "source": [
+    "import math\n",
+    "print \"%.3f\" % math.pi"
+   ]
   },
   {
    "cell_type": "markdown",
@@ -568,12 +611,70 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 19,
    "metadata": {
     "collapsed": false
    },
-   "outputs": [],
-   "source": []
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "['__doc__',\n",
+       " '__file__',\n",
+       " '__name__',\n",
+       " '__package__',\n",
+       " 'acos',\n",
+       " 'acosh',\n",
+       " 'asin',\n",
+       " 'asinh',\n",
+       " 'atan',\n",
+       " 'atan2',\n",
+       " 'atanh',\n",
+       " 'ceil',\n",
+       " 'copysign',\n",
+       " 'cos',\n",
+       " 'cosh',\n",
+       " 'degrees',\n",
+       " 'e',\n",
+       " 'erf',\n",
+       " 'erfc',\n",
+       " 'exp',\n",
+       " 'expm1',\n",
+       " 'fabs',\n",
+       " 'factorial',\n",
+       " 'floor',\n",
+       " 'fmod',\n",
+       " 'frexp',\n",
+       " 'fsum',\n",
+       " 'gamma',\n",
+       " 'hypot',\n",
+       " 'isinf',\n",
+       " 'isnan',\n",
+       " 'ldexp',\n",
+       " 'lgamma',\n",
+       " 'log',\n",
+       " 'log10',\n",
+       " 'log1p',\n",
+       " 'modf',\n",
+       " 'pi',\n",
+       " 'pow',\n",
+       " 'radians',\n",
+       " 'sin',\n",
+       " 'sinh',\n",
+       " 'sqrt',\n",
+       " 'tan',\n",
+       " 'tanh',\n",
+       " 'trunc']"
+      ]
+     },
+     "execution_count": 19,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "dir(math)"
+   ]
   },
   {
    "cell_type": "markdown",
@@ -582,26 +683,43 @@
     "## <span style=\"color:blue\">Exercise: Find errors in the coding of a formula</span>\n",
     "Given a quadratic equation,\n",
     "$$ax^2 + bx + c = 0,$$\n",
-    "$$x1 = −b+\\frac{\\sqrt{b^2 −4ac}}{2a},$$ and\n",
-    "$$x2 = −b−\\frac{\\sqrt{b^2 −4ac}}{2a}.$$\n",
+    "$$x1 = \\frac{−b+\\sqrt{b^2 −4ac}}{2a},$$ and\n",
+    "$$x2 = \\frac{−b−\\sqrt{b^2 −4ac}}{2a}.$$\n",
     "Why does the following program not work correctly?"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 22,
    "metadata": {
     "collapsed": false
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "(-0.25+0.968245836552j) (-0.25-0.968245836552j)\n"
+     ]
+    }
+   ],
    "source": [
     "a = 2; b = 1; c = 2\n",
-    "from math import sqrt\n",
+    "from cmath import sqrt\n",
     "q = sqrt(b*b - 4*a*c)\n",
-    "x1 = (-b + q)/2*a\n",
-    "x2 = (-b - q)/2*a\n",
+    "x1 = (-b + q)/(2*a)\n",
+    "x2 = (-b - q)/(2*a)\n",
     "print x1, x2"
    ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": []
   }
  ],
  "metadata": {