Moved the exercises for lecture 3 into the lecture notes.

Author: Christian Jacobs

notebook/Lecture-3-Introduction-to-programming-for-geoscientists-Exercises.ipynb

@@ -8,11 +8,11 @@
   {
    "cells": [
     {
-     "cell_type": "heading",
-     "level": 1,
+     "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "Introduction to programming for Geoscientists (through Python)"
+      "#Introduction to programming for Geoscientists (through Python)\n",
+      "###[Gerard Gorman](http://www.imperial.ac.uk/people/g.gorman), [Christian Jacobs](http://www.imperial.ac.uk/people/c.jacobs10)"
      ]
     },
     {
@@ -21,9 +21,9 @@
      "source": [
       "#Lecture 3: Input data and error handling\n",
       "\n",
-      "[Gerard J. Gorman](http://www.imperial.ac.uk/people/g.gorman) <g.gorman@imperial.ac.uk>\n",
-      "\n",
-      "Learning objectives: You will learn how to read input data into a Python program. You will be able to catch run-time errors and handle them gracefully rather than the program simply failing."
+      "Learning objectives:\n",
+      "* Learn how to read input data into a Python program.\n",
+      "* Be able to catch run-time errors and handle them gracefully rather than the program simply failing."
      ]
     },
     {
@@ -324,6 +324,49 @@
      ],
      "prompt_number": 8
     },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "## <span style=\"color:blue\">Exercise 1: Make an interactive program</span>\n",
+      "Make a program that (i) asks the user for a temperature in Fahrenheit degrees and reads the number; (ii) computes the corresponding temperature in Celsius degrees; and (iii) prints out the temperature in the Celsius scale."
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "## <span style=\"color:blue\">Exercise 2: Prompt the user for input to a formula</span>\n",
+      "Consider the simplest program for evaluting the formula $y(t) = v_0 t \u2212 0.5gt^2$:"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "v0 = 3; g = 9.81; t = 0.6\n",
+      "y = v0*t - 0.5*g*t**2\n",
+      "print y"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "Modify this code so that the program asks the user questions *t=?* and *v0=?*, and then gets *t* and *v0* from the user's input through the keyboard."
+     ]
+    },
     {
      "cell_type": "markdown",
      "metadata": {},
@@ -629,6 +672,89 @@
       }
      ],
      "prompt_number": 16
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "## <span style=\"color:blue\">Exercise 3: Use exceptions</span>\n",
+      "Extend the program from Exercise 1 with a try-except block to handle the potential error that the user enters nothing (or invalid data such as a letter) for the Fahrenheit temperature."
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "## <span style=\"color:blue\">Exercise 4a: Make the program from Exercise 2 safer</span>\n",
+      "Extend the program from Exercise 2 to include exception handling such that missing (or invalid) values for *t* and *v0* are detected. In the *except ValueError* block, use the raw_input function to ask the user for input data once more."
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "## <span style=\"color:blue\">Exercise 4b: Test more in the program</span>\n",
+      "Test if the *t* value read in the program from the previous exercise lies between $0$ and ${2v_0}/{g}$. If not, print a message and abort execution."
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "## <span style=\"color:blue\">Exercise 4c: Raising an exception</span>\n",
+      "Instead of printing an error message and aborting the program explicitly, raise a *ValueError* exception in the *if* test on legal *t* values in the program from the previous exercise. Include the legal interval for *t* in the exception message."
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
+    },
+    {
+     "cell_type": "markdown",
+     "metadata": {},
+     "source": [
+      "## <span style=\"color:blue\">Exercise 5: Compute the distance it takes to stop a car</span>\n",
+      "A car driver, driving at velocity $v_0$, suddenly puts on the brake. What braking distance $d$ is needed to stop the car? One can derive, from basic physics, that</br>\n",
+      "$d = 0.5\\frac{v_0^2}{\\mu g}$</br>\n",
+      "Make a program for computing $d$ using the above formula when the initial car velocity $v_0$ and the friction coefficient $\\mu$ are provided via the raw_input function. Run the\n",
+      "program for two cases: $v_0$ = 120 and $v_0$ = 50 km/h, both with $\\mu$ = 0.3 ($\\mu$ is dimensionless). (Remember to convert the velocity from km/h to m/s before inserting the value in the formula!)"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [],
+     "language": "python",
+     "metadata": {},
+     "outputs": []
     }
    ],
    "metadata": {}