{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {
    "collapsed": true
   },
   "source": [
    "# Solutions\n",
    "## Problem 1\n",
    "Implement the Min-Max scaling function ($X'=a+{\\frac {\\left(X-X_{\\min }\\right)\\left(b-a\\right)}{X_{\\max }-X_{\\min }}}$) with the parameters:\n",
    "\n",
    "$X_{\\min }=0$\n",
    "\n",
    "$X_{\\max }=255$\n",
    "\n",
    "$a=0.1$\n",
    "\n",
    "$b=0.9$"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "# Problem 1 - Implement Min-Max scaling for grayscale image data\n",
    "def normalize_grayscale(image_data):\n",
    "    \"\"\"\n",
    "    Normalize the image data with Min-Max scaling to a range of [0.1, 0.9]\n",
    "    :param image_data: The image data to be normalized\n",
    "    :return: Normalized image data\n",
    "    \"\"\"\n",
    "    a = 0.1\n",
    "    b = 0.9\n",
    "    grayscale_min = 0\n",
    "    grayscale_max = 255\n",
    "    return a + ( ( (image_data - grayscale_min)*(b - a) )/( grayscale_max - grayscale_min ) )"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Problem 2\n",
    "- Use [tf.placeholder()](https://www.tensorflow.org/api_docs/python/io_ops.html#placeholder) for `features` and `labels` since they are the inputs to the model.\n",
    "- Any math operations must have the same type on both sides of the operator.  The weights are float32, so the `features` and `labels` must also be float32.\n",
    "- Use [tf.Variable()](https://www.tensorflow.org/api_docs/python/state_ops.html#Variable) to allow `weights` and `biases` to be modified.\n",
    "- The `weights` must be the dimensions of features by labels.  The number of features is the size of the image, 28*28=784.  The size of labels is 10.\n",
    "- The `biases` must be the dimensions of the labels, which is 10."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "features_count = 784\n",
    "labels_count = 10\n",
    "\n",
    "# Problem 2 - Set the features and labels tensors\n",
    "features = tf.placeholder(tf.float32)\n",
    "labels = tf.placeholder(tf.float32)\n",
    "\n",
    "# Problem 2 - Set the weights and biases tensors\n",
    "weights = tf.Variable(tf.truncated_normal((features_count, labels_count)))\n",
    "biases = tf.Variable(tf.zeros(labels_count))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Problem 3\n",
    "Configuration 1\n",
    "* **Epochs:** 1\n",
    "* **Learning Rate:** 0.1\n",
    "\n",
    "Configuration 2\n",
    "* **Epochs:** 4 or 5\n",
    "* **Learning Rate:** 0.2"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.5.2"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 0
}