Homework changes

.ipynb_checkpoints/Homework-0-checkpoint.ipynb

@@ -0,0 +1,286 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Homework 0"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "The goal of this homework is to practice the skills learned in Lecture 2. These skills will be essential for the rest of this course."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Before starting to work on this homework, **make a new folder** named ```hw0-submission```   in your private repo and download ```Homework-0.ipynb``` to that folder."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Let's make sure that you placed everything in the correct folder"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "You did everything correctly. Congrats!\n"
+     ]
+    }
+   ],
+   "source": [
+    "import os\n",
+    "error = False\n",
+    "\n",
+    "if os.path.basename(os.path.realpath('.')) != \"hw0-submission\":\n",
+    "    print \"The name of the current directory should be 'hw0-submission'\"\n",
+    "    error = True\n",
+    "\n",
+    "if not error:\n",
+    "    print \"You did everything correctly. Congrats!\"\n",
+    "    "
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Now, assuming that everything is in their correct place, you should ``git add`` all the new directories/files and make your initial ```git commit```."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## This is a Markdown cell"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "# Insert and edit your own markdown cell *below*. Write your favorite quote"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "hello world\n"
+     ]
+    }
+   ],
+   "source": [
+    "# This is a code cell. Try executing it.\n",
+    "print \"hello world\""
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Write a function that takes as argument a string and returns its 3-letter suffix. If the string is shorter than 3 letters, return the whole string."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "def suffix_3(string):\n",
+    "    \"\"\"\n",
+    "    Returns the 3-letter suffix.\n",
+    "    \n",
+    "    Parameters:\n",
+    "        string: str\n",
+    "    \n",
+    "    Returns:\n",
+    "        suffix: str\n",
+    "        If `string` is more than 3-letters long, `suffix` is its 3-letter suffix. Otherwise, `suffix` is the same as `string`.\n",
+    "    \"\"\"\n",
+    "    "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "print suffix_3(\"Hi!\")\n",
+    "print suffix_3(\"Superb\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "When you finish with the above function, don't forget to ```add``` and ```commit``` to your local git repository."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Let's print the versions of some packages that we will be using in the future. If any of these packages are not present, ```conda install``` them."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "import numpy\n",
+    "print 'numpy:', numpy.__version__\n",
+    "\n",
+    "import scipy\n",
+    "print 'scipy:', scipy.__version__\n",
+    "\n",
+    "import matplotlib\n",
+    "print 'matplotlib:', matplotlib.__version__\n",
+    "\n",
+    "import sklearn\n",
+    "print 'scikit-learn:', sklearn.__version__\n",
+    "\n",
+    "import pandas\n",
+    "print 'pandas:', pandas.__version__"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Write a function that takes as argument a 2D list representing a matrix **M** and returns a boolean indicating whether **M** is an orthogonal matrix."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": [
+    "import numpy\n",
+    "\n",
+    "def is_matrix_orthogonal(M):\n",
+    "    \"\"\"\n",
+    "    Returns whether M is an orthogonal matrix.\n",
+    "    \n",
+    "    Parameters:\n",
+    "        M: 2D list\n",
+    "    \n",
+    "    Returns:\n",
+    "        is_orthogonal: boolean\n",
+    "    \"\"\"\n",
+    "    "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false,
+    "scrolled": false
+   },
+   "outputs": [],
+   "source": [
+    "print is_matrix_orthogonal([[1, 0], [0, -1]])\n",
+    "print is_matrix_orthogonal([[-1.2396, -4.3801, -1.7737], [-1.3121, -2.9193, -4.5496], [-2.1143, 0.0363, 0.2022]])\n",
+    "print is_matrix_orthogonal([[-0.8185, 0.5740, -0.0249], [-0.2510, -0.3183, 0.9142], [-0.5168, -0.7544, -0.4046]])"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "When you finish with the above function, don't forget to ```add``` and ```commit``` to your local git repository."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## Submitting"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "Now, you can push your changes to Github."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [],
+   "source": [
+    "# Code for setting the style of the notebook\n",
+    "from IPython.core.display import HTML\n",
+    "def css_styling():\n",
+    "    styles = open(\"../../theme/custom.css\", \"r\").read()\n",
+    "    return HTML(styles)\n",
+    "css_styling()"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 2",
+   "language": "python",
+   "name": "python2"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.11"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 0
+}