{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Loops, Conditions, and Programming"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Logical and Relational Operations"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "ans =\n",
      "     0\n"
     ]
    }
   ],
   "source": [
    "% less than\n",
    "format compact\n",
    "x = 2;\n",
    "y = -2;\n",
    "x < y   % test if x is smaller than y (0 is flase, 1 is true)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 27,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "ans =\n",
      "     0\n"
     ]
    }
   ],
   "source": [
    "% greater than\n",
    "y > x"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "ans =\n",
      "     0     1     1     0     0\n"
     ]
    }
   ],
   "source": [
    "% for vectors\n",
    "x = [-1 2 0 4 6];\n",
    "y = [2 1 -1 5 9];\n",
    "x > y  % evaluates each element"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 29,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "ans =\n",
      "     1     0     0     1     1\n"
     ]
    }
   ],
   "source": [
    "% less-than or equal to\n",
    "x <= y"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 30,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "ans =\n",
      "     0     1     1     0     0\n"
     ]
    }
   ],
   "source": [
    "% greater-than or equal to\n",
    "x >= y"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 31,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "ans =\n",
      "     0     0     0     0     0\n"
     ]
    }
   ],
   "source": [
    "% equal to\n",
    "x == y"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Logical Operators"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "& AND<br>\n",
    "~ NOT<br>\n",
    "| OR<br>\n",
    "XOR Exclusive OR"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 32,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "x = [1 0 1 1 0 0];\n",
    "y = [0 1 0 1 0 1];"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 33,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "ans =\n",
      "     0     0     0     1     0     0\n"
     ]
    }
   ],
   "source": [
    "% AND\n",
    "x & y"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 34,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "ans =\n",
      "     0     1     0     0     1     1\n"
     ]
    }
   ],
   "source": [
    "% NOT\n",
    "~x"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 35,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "ans =\n",
      "     1     1     1     1     0     1\n"
     ]
    }
   ],
   "source": [
    "% OR\n",
    "x | y"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### Conditions"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### If and Else"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 36,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Hello World!!\n",
      "     3\n"
     ]
    }
   ],
   "source": [
    "% if statements are handled much the same as any other language\n",
    "clear all\n",
    "x = 3;\n",
    "if x < 4\n",
    "    disp('Hello World!!')\n",
    "    disp(x)\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 37,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "y =\n",
      "    1.0986\n"
     ]
    }
   ],
   "source": [
    "% same goes for if-else\n",
    "if x > 0\n",
    "    y = log(x)\n",
    "else\n",
    "    disp('Log args can not be <= zero!')\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 38,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Log args can not be <= zero!\n"
     ]
    }
   ],
   "source": [
    "x = -3;\n",
    "if x > 0\n",
    "    y = log(x)\n",
    "else\n",
    "    disp('Log args can not be <= zero!')\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 39,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Log args can not be <= zero!\n"
     ]
    }
   ],
   "source": [
    "% we can also output an audible alert using 'beep'\n",
    "if x > 0\n",
    "    y = log(x)\n",
    "else\n",
    "    beep\n",
    "    disp('Log args can not be <= zero!')\n",
    "end"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Else-If"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 40,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Youre good to go!!!\n"
     ]
    }
   ],
   "source": [
    "clear all\n",
    "age = 37;\n",
    "if age < 16\n",
    "    disp('You are too young to apply!')\n",
    "elseif age < 18\n",
    "    disp('You can apply for a learners permit')\n",
    "elseif age < 70\n",
    "    disp('Youre good to go!!!')\n",
    "else\n",
    "    disp('You need a provisional license')\n",
    "end"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### While Loops"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 41,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "3\n"
     ]
    }
   ],
   "source": [
    "% simple example\n",
    "clear all\n",
    "k = 0;\n",
    "while k < 3\n",
    "    k = k +1;\n",
    "end\n",
    "disp(k)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "### For Loops"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 42,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "i =\n",
      "     1\n",
      "i =\n",
      "     2\n",
      "i =\n",
      "     3\n"
     ]
    }
   ],
   "source": [
    "% here is a simple for loop\n",
    "for i = [1 2 3]\n",
    "    i\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "i =\n",
      "     3\n"
     ]
    }
   ],
   "source": [
    "% the variable i is now 3\n",
    "i"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 44,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "ans =\n",
      "     1\n",
      "ans =\n",
      "     2\n",
      "ans =\n",
      "     4\n",
      "ans =\n",
      "     8\n",
      "ans =\n",
      "    16\n",
      "ans =\n",
      "    32\n",
      "ans =\n",
      "    64\n",
      "ans =\n",
      "   128\n",
      "ans =\n",
      "   256\n"
     ]
    }
   ],
   "source": [
    "% another example\n",
    "for k = 0:8\n",
    "    2^k\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 45,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "v =\n",
      "     1     4     7    10\n",
      "v =\n",
      "     1     2     3     4\n"
     ]
    }
   ],
   "source": [
    "% another example \n",
    "v = [1:3:10]\n",
    "for j = 1:4\n",
    "    v(j) = j;\n",
    "end\n",
    "v"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Notes on for loop methodology"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The previous example illustrates how a for loop works, but it is not the most efficient manner in which to iterate through a matrix an perform calculations on each element."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 46,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "A =\n",
      "     1     3     2\n",
      "     2     2     1\n",
      "     3     1     3\n"
     ]
    }
   ],
   "source": [
    "% this is the preferred manner\n",
    "clear all\n",
    "A = [[1 2 3]' [3 2 1]' [2 1 3]']"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 47,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "A =\n",
      "     1     3     2\n",
      "     1    -1    -1\n",
      "     3     1     3\n",
      "A =\n",
      "     1     3     2\n",
      "     1    -1    -1\n",
      "     2     2     4\n"
     ]
    }
   ],
   "source": [
    "B = A;\n",
    "for j = 2:3\n",
    "    A(j,:) = A(j,:) - A(j-1,:)\n",
    "end"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 48,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "7\n"
     ]
    }
   ],
   "source": [
    "clear all\n",
    "scores = [30 65 90 87 56 34 82 99 90];\n",
    "count = 0;\n",
    "for k = 1:length(scores)\n",
    "    if scores(k) > 50\n",
    "        count = count + 1;\n",
    "    end\n",
    "end\n",
    "disp(count)"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Matlab",
   "language": "matlab",
   "name": "matlab"
  },
  "language_info": {
   "codemirror_mode": "octave",
   "file_extension": ".m",
   "help_links": [
    {
     "text": "MetaKernel Magics",
     "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
    }
   ],
   "mimetype": "text/x-matlab",
   "name": "matlab",
   "version": "0.8.0"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 0
}