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+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Text Mining (concepts) - Exercises 6, 7, 8 et 9\n",
+    "In the following notebook, we are aiming at calculating the similarities between the following movies:\n",
+    " - (\"Harry Potter 1\",\"671\"),\n",
+    " - (\"Harry Potter 2\",\"672\"),\n",
+    " - (\"The lord of the ring 1\", \"120\"),\n",
+    " - (\"The Hobbit 1\", \"49051\"),\n",
+    "    \n",
+    "Using the outcome of Exercise 2, extract a summary of those 4 movies (including actors).\n",
+    "In the present notebook, we will calculate the vectorized version of the 4 documents and calculate the cosine similarities between each pair of movies. "
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Packages"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import math\n",
+    "from typing import Dict\n",
+    "from typing import List\n",
+    "from typing import Optional\n",
+    "from os import sep\n",
+    "from os import walk\n",
+    "\n",
+    "import numpy\n",
+    "#@COMPLETE : add here missing packages for Text Mining\n",
+    "# For NLTK, do not forget to download the required ressources (punkts, stopwords)\n"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Classes"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class Token:\n",
+    "    \"\"\"\n",
+    "    Class representing a given token. It stores the string representing the token, its identifier and the number of\n",
+    "    documents\n",
+    "\n",
+    "    |\n",
+    "\n",
+    "    The instance attributes are:\n",
+    "\n",
+    "    token_id:\n",
+    "        Identifier of the token.\n",
+    "    token:\n",
+    "        String representing the token.\n",
+    "    docs:\n",
+    "        Identifiers of documents containing the token.\n",
+    "    \"\"\"\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    token_id: int\n",
+    "    token: str\n",
+    "    docs: List[int]\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def __init__(self, token_id: int, token: str):\n",
+    "        \"\"\"\n",
+    "        Constructor.\n",
+    "\n",
+    "        :param token_id: Identifier of the token.\n",
+    "        :param token: String representing the token.\n",
+    "        \"\"\"\n",
+    "        self.token_id = token_id\n",
+    "        self.token = token\n",
+    "        self.docs = []\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def get_idf(self, nb_docs: int) -> float:\n",
+    "        \"\"\"\n",
+    "        Compute the IDF factor of a token.\n",
+    "\n",
+    "        :param nb_docs: Total number of documents in the corpus.\n",
+    "        :return: IDF factor.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        if len(self.docs) == 0:\n",
+    "            return 0.0\n",
+    "        return math.log(float(nb_docs) / float(len(self.docs)))\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class Doc:\n",
+    "    \"\"\"\n",
+    "    This class represents an instance of a document.\n",
+    "\n",
+    "    |\n",
+    "\n",
+    "    The instance attributes are:\n",
+    "\n",
+    "    url:\n",
+    "        URL of the document (if defined).\n",
+    "    doc_id:\n",
+    "        Identifier of the document.\n",
+    "    text:\n",
+    "        Text of the document to analyse.\n",
+    "    vector:\n",
+    "        Vector representing the document.\n",
+    "    tokens:\n",
+    "        List of tokens i order of appearances. A same token may appear several times.\n",
+    "    \"\"\"\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    url: Optional[str]\n",
+    "    doc_id: int\n",
+    "    text: str\n",
+    "    vector: numpy.ndarray\n",
+    "    tokens: List[Token]\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def __init__(self, doc_id: int, text: str, url: Optional[str] = None):\n",
+    "        \"\"\"\n",
+    "        Constructor.\n",
+    "\n",
+    "        :param doc_id:\n",
+    "        :param text: Text of the document (brut).\n",
+    "        :param url: URL of the document (if any).\n",
+    "        \"\"\"\n",
+    "        self.url = url\n",
+    "        self.doc_id = doc_id\n",
+    "        self.text = text\n",
+    "        self.vector = None\n",
+    "        self.tokens = None\n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class DocCorpus:\n",
+    "    \"\"\"\n",
+    "    This class represents a corpus of documents and the corresponding dictionary of tokens contained.\n",
+    "\n",
+    "    |\n",
+    "\n",
+    "    The instance attributes are:\n",
+    "\n",
+    "    docs:\n",
+    "        List of documents.\n",
+    "    tokens:\n",
+    "        Dictionary of tokens (strings are the key).\n",
+    "    ids:\n",
+    "        Dictionary of tokens (identifiers are the key).\n",
+    "    method:\n",
+    "        String representing the method used for analysing (\"TF-IDF\" or \"Doc2Vec\").\n",
+    "    nb_dims:\n",
+    "        Number of dimensions of the semantic space.\n",
+    "    stopwords:\n",
+    "        List of stopwords to eliminate from the analysis. By default, it's the classic English list.\n",
+    "    \"\"\"\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    docs = List[Doc]\n",
+    "    tokens: Dict[str, Token]\n",
+    "    ids: Dict[int, Token]\n",
+    "    method: str\n",
+    "    nb_dims: int\n",
+    "    stopwords: List[str]\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def __init__(self):\n",
+    "        \"\"\"\n",
+    "        Constructor.\n",
+    "        \"\"\"\n",
+    "        self.docs = []\n",
+    "        self.tokens = dict()\n",
+    "        self.ids = dict()\n",
+    "        self.method = \"Doc2Vec\"\n",
+    "        self.nb_dims = 0\n",
+    "        self.n_tokens = 0\n",
+    "        self.stopwords = stopwords.words('english')\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def set_method(self, name) -> None:\n",
+    "        \"\"\"\n",
+    "        Change the parameter.\n",
+    "\n",
+    "        :param name: Name of the method.\n",
+    "        \"\"\"\n",
+    "        self.method = name\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def add_doc(self, new_doc: str, url: Optional[str] = None) -> None:\n",
+    "        \"\"\"\n",
+    "        Add a string representing a document to the corpus and provides an\n",
+    "        identifier to the document.\n",
+    "\n",
+    "        :param new_doc: New document.\n",
+    "        :param url: URL of the document (if any)\n",
+    "        \"\"\"\n",
+    "        new_id = len(self.docs)\n",
+    "        self.docs.append(Doc(new_id, new_doc, url))\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def add_docs(self, docs: List[str]) -> None:\n",
+    "        \"\"\"\n",
+    "        Add a list of strings representing documents to the corpus. Each document receives an\n",
+    "        identifier.\n",
+    "\n",
+    "        :param docs: List of documents.\n",
+    "        \"\"\"\n",
+    "        for cur_doc in docs:\n",
+    "            self.add_doc(cur_doc)\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def build_vectors(self) -> None:\n",
+    "        \"\"\"\n",
+    "        Build the vectors for the documents of the corpus based on the current method.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        if self.method == \"Doc2Vec\":\n",
+    "            self.build_doc2vec()\n",
+    "        elif self.method == \"TF-IDF\":\n",
+    "            self.build_tf_idf()\n",
+    "        else:\n",
+    "            raise ValueError(\"'\" + self.method + \"': Invalid building method\")\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def get_term_document_matrix(self) -> numpy.ndarray:\n",
+    "        \"\"\"\n",
+    "        Build a document-token matrix with the weights as values.\n",
+    "\n",
+    "        :return: Document-token matrix.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        matrix = numpy.zeros(shape=(len(self.docs),self.nb_dims))\n",
+    "        for cur_doc in self.docs:\n",
+    "            i = 0\n",
+    "            for token in cur_doc.vector:\n",
+    "                matrix[cur_doc.doc_id, i] = token\n",
+    "                i += 1\n",
+    "        return matrix\n",
+    "    \n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def add_token(self, cur_doc: Doc, token_str: str) -> None:\n",
+    "        \"\"\"Add a token in string format to the Doc Corpus\n",
+    "        \n",
+    "        Find the identifier of the current token in the dictionary.\n",
+    "        If not present, create a new Token instance\n",
+    "        \n",
+    "        Attach the token to the current document\n",
+    "        \n",
+    "        Finally, link the document to the Token object\n",
+    "        \n",
+    "        :param cur_doc : the current document from which the token is extracted\n",
+    "        :token_str : the token after cleaning steps (stopwords, stemming, ...)\n",
+    "        \n",
+    "        \"\"\"\n",
+    "        # Find the identifier of the current token in the dictionary\n",
+    "        if token_str not in self.tokens.keys():\n",
+    "            token_id = len(self.tokens)\n",
+    "            token = Token(token_id, token_str)\n",
+    "            self.tokens[token_str] = token\n",
+    "            self.ids[token_id] = token\n",
+    "            self.n_tokens = len(self.tokens)\n",
+    "        else:\n",
+    "            token = self.tokens[token_str]\n",
+    "            \n",
+    "        # Add the token\n",
+    "        cur_doc.tokens.append(token)\n",
+    "        \n",
+    "        # Add a reference count if necessary\n",
+    "        if cur_doc.doc_id not in token.docs:\n",
+    "            token.docs.append(cur_doc.doc_id)\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def extract_tokens(self) -> None:\n",
+    "        \"\"\"\n",
+    "        Extract the tokens from the text of the documents. In practice, for each document, the methods\n",
+    "        do the following steps:\n",
+    "\n",
+    "        1. The text is transform in lowercase.\n",
+    "\n",
+    "        2. The text is tokenised.\n",
+    "\n",
+    "        3. Stopwords are removed.\n",
+    "\n",
+    "        The method words incrementally. Once a document is treated, it will not be re-treated in successive\n",
+    "        calls.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        # @COMPLETE : create a stemmer\n",
+    "        for cur_doc in self.docs:\n",
+    "            \n",
+    "            if cur_doc.tokens is not None:\n",
+    "                continue\n",
+    "            cur_doc.tokens = []\n",
+    "            text = cur_doc.text\n",
+    "            \n",
+    "            # @COMPLETE : get text to lowercase\n",
+    "            for extracted_token in nltk.word_tokenize(text):\n",
+    "\n",
+    "                #  @COMPLETE : Retains only the stem of non stopwords and punctuation               \n",
+    "                self.add_token(cur_doc, token_str)\n",
+    "\n",
+    "\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def build_tf_idf(self) -> None:\n",
+    "        \"\"\"\n",
+    "        Build the vectors of the corpus using the TF-IDF approach.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        vectors = []\n",
+    "        self.extract_tokens()\n",
+    "\n",
+    "        # Step 1: For each document, compute the relative frequencies of each token (TF).\n",
+    "        for cur_doc in self.docs:\n",
+    "            vector = dict()  # Dictionary representing a vector of pairs (token_id,nb_occurrences)\n",
+    "            nb_occurrences = 0\n",
+    "            # @COMPLETE : calculate a vector TF for each document and append to vectors\n",
+    "            \n",
+    "\n",
+    "        # Step 2: Build the TF-IDF vectors by multiplying the relative frequencies by the IDF factor.\n",
+    "        self.nb_dims = self.n_tokens\n",
+    "        for cur_doc in self.docs:\n",
+    "            cur_doc.vector = numpy.zeros(shape=self.nb_dims)\n",
+    "            # @COMPLETE : calculate a vector TF-IDF and store it to cur_doc.vector\n",
+    "            # Hint : make use of the \"get_idf() method of the Token Class\"\n",
+    "\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def build_doc2vec(self) -> None:\n",
+    "        \"\"\"\n",
+    "        Build the vectors using the doc2vec approach.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        self.extract_tokens()\n",
+    "        corpus = []\n",
+    "        for doc in self.docs:\n",
+    "            tokens = []\n",
+    "            for token in doc.tokens:\n",
+    "                tokens.append(token.token)\n",
+    "            corpus.append(tokens)\n",
+    "            \n",
+    "        corpus = [\n",
+    "            TaggedDocument(words, ['d{}'.format(idx)])\n",
+    "            for idx, words in enumerate(corpus)\n",
+    "        ]\n",
+    "        \n",
+    "        # @COMPLETE : create a doc2vec model with 5 dimension and min_count=1\n",
+    "        # Add the resulting vector (mode.dv) in self.docs[i].vector\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "class TokenSorter:\n",
+    "    \"\"\"\n",
+    "    Class to sort a list of tokens by a certain value.\n",
+    "    |\n",
+    "\n",
+    "    The instance attributes are:\n",
+    "\n",
+    "    tokens:\n",
+    "        List of tokens to sort.\n",
+    "    reverse:\n",
+    "        Must the token be ranked descending (False) or ascending (True)\n",
+    "    \"\"\"\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    class TokenRef:\n",
+    "        \"\"\"\n",
+    "        Class to represent a reference to a token.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        # ---------------------------------------------------------------------\n",
+    "        token: Token\n",
+    "        value: float\n",
+    "\n",
+    "        # ---------------------------------------------------------------------\n",
+    "        def __init__(self, token: Token, value: float):\n",
+    "            self.token = token\n",
+    "            self.value = value\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    tokens: List[TokenRef]\n",
+    "    reverse: bool\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def __init__(self):\n",
+    "        \"\"\"\n",
+    "        Constructor.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        self.tokens = []\n",
+    "        self.reverse = False\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def build(self, tokens, value, reverse: bool) -> None:\n",
+    "        \"\"\"\n",
+    "        Build the list of token to sort.\n",
+    "\n",
+    "        :param tokens: Tokens to sort.\n",
+    "        :param value: Lambda function that will be used to build the value associated to each token to sort.\n",
+    "        :param reverse: Should the token be sorted in descending (True) of ascending (False) order.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        for token in tokens.values():\n",
+    "            self.add_token(token, value(token))\n",
+    "        self.reverse = reverse\n",
+    "        self.sort()\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def add_token(self, token: Token, value: float) -> None:\n",
+    "        \"\"\"\n",
+    "        Add a token to the list.\n",
+    "\n",
+    "        :param token: Token to add.\n",
+    "        :param value: Value that will be used to sort the tokens.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        self.tokens.append(TokenSorter.TokenRef(token=token, value=float(value)))\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def sort(self) -> None:\n",
+    "        \"\"\"\n",
+    "        Sort the tokens.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        self.tokens.sort(reverse=self.reverse, key=lambda token: token.value)\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def get_token(self, pos: int) -> str:\n",
+    "        \"\"\"\n",
+    "        Get a given token of the list.\n",
+    "\n",
+    "        :param pos: Position of the token in the list.\n",
+    "        :return: String representing the token.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        return self.tokens[pos].token.token\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def get_value(self, pos: int) -> str:\n",
+    "        \"\"\"\n",
+    "        Get a value of a given token in the list.\n",
+    "\n",
+    "        :param pos: Position of the token in the list.\n",
+    "        :return: Value of the token used for the sorting.\n",
+    "        \"\"\"\n",
+    "\n",
+    "        return self.tokens[pos].value\n",
+    "\n",
+    "    # -------------------------------------------------------------------------\n",
+    "    def print(self, title: str, nb : int) -> None:\n",
+    "        \"\"\"\n",
+    "        Print a given number of top ranked tokens with a title and their values.\n",
+    "\n",
+    "        :param title: Title to print.\n",
+    "        :param nb:  Number of tokens to print.\n",
+    "        \"\"\"\n",
+    "        print(title)\n",
+    "        if nb > len(self.tokens):\n",
+    "            nb = len(self.tokens)\n",
+    "        for i in range(0,nb):\n",
+    "            print(f\"  Token: {self.get_token(i)} ({self.get_value(i):.2f})\")\n"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Functions"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def print_matrix(name:str, matrix: numpy.ndarray) -> None:\n",
+    "    \"\"\"\n",
+    "    Simple method to print a little matrix nicely.\n",
+    "\n",
+    "    :param name:  Name of the matrix.\n",
+    "    :param matrix:  Matrix to print.\n",
+    "    \"\"\"\n",
+    "    nb_lines = matrix.shape[0]\n",
+    "    nb_cols = matrix.shape[1]\n",
+    "    spaces = \" \" * (len(name) + 1)\n",
+    "    title_line = nb_lines % 2\n",
+    "    for i in range(0, nb_lines):\n",
+    "        if i == title_line:\n",
+    "            print(name + \"=\", end=\"\")\n",
+    "        else:\n",
+    "            print(spaces, end=\"\")\n",
+    "        print(\"( \", end=\"\")\n",
+    "        for j in range(0, nb_cols):\n",
+    "            print( \"{:.3f}\".format(matrix[i,j]), end=\" \")\n",
+    "        print(\")\",)\n",
+    "\n",
+    "\n",
+    "def create_corpus(path: str) -> DocCorpus:\n",
+    "    \"\"\"\n",
+    "    From a list of docs located at path, create a corpus\n",
+    "    \n",
+    "    A DocCorpus document is build and populated with all the \"doc\" documents\n",
+    "    located at the path\n",
+    "    \n",
+    "    :param path : string description of the path\n",
+    "    \n",
+    "    :return : DocCorpus representing the corpus of all the documents\n",
+    "    \"\"\"\n",
+    "    # Instantiate a DocCorpus object\n",
+    "    the_corpus = DocCorpus()\n",
+    "\n",
+    "    # Look for all the files in a directory\n",
+    "    files = []\n",
+    "    dir_to_analyse = \"./docs\"\n",
+    "    for (_, _, file_names) in walk(dir_to_analyse):\n",
+    "        files.extend(file_names)\n",
+    "        break\n",
+    "\n",
+    "    # Add the context to the corpus\n",
+    "    for doc_to_analyse in files:\n",
+    "        # Treat only files beginning with \"doc\"\n",
+    "        if doc_to_analyse[:3] != \"doc\":\n",
+    "            continue\n",
+    "\n",
+    "        filename = dir_to_analyse + sep + doc_to_analyse\n",
+    "        file = open(file=filename, mode=\"r\", encoding=\"utf-8\")\n",
+    "        the_corpus.add_doc(file.read(), filename)\n",
+    "    \n",
+    "    return the_corpus\n",
+    "    "
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Exercise 6 : token extraction and dimensionality reduction\n",
+    "Complete the implemention of implementation the \"extract_tokens\" method from the DocCorpus class.\n",
+    "The method should :\n",
+    "- extract word tokens\n",
+    "- remove the case (lowercase only)\n",
+    "- remove punctuation\n",
+    "- remove stopwords\n",
+    "- perform stemming"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "the_corpus = create_corpus(\"./docs\")# Create a corpus instance\n",
+    "the_corpus.extract_tokens() # Extract the tokens from the corpus\n",
+    "\n",
+    "\n",
+    "# -------------------------------------------------------------------------------------------------\n",
+    "# Sort the tokens by the number of documents in which they appear\n",
+    "sort_by_docs = TokenSorter()\n",
+    "sort_by_docs.build(tokens=the_corpus.tokens, value=lambda token: len(token.docs), reverse=True)\n",
+    "sort_by_docs.print(title=\"Most appearing tokens (Nb Documents):\",nb=5)\n",
+    "\n",
+    "# Sort the tokens by their idf factor\n",
+    "sort_by_iDF = TokenSorter()\n",
+    "sort_by_iDF.build(tokens=the_corpus.tokens, value=lambda token: token.get_idf(len(the_corpus.docs)), reverse=True)\n",
+    "sort_by_iDF.print(title=\"Most discriminant  tokens (idf):\",nb=5)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Exercise 7 : vectorization with TF-IDF\n",
+    "Complete the implemention of the TF-IDF method from the DocCorpus class."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "the_corpus.build_tf_idf()\n",
+    "term_document_matrix = the_corpus.get_term_document_matrix()\n",
+    "print_matrix(\"Docs\", term_document_matrix)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Exercise 8 : vectorization with Doc2Vec\n",
+    "Complete the implemention of the Doc2Vec method from the DocCorpus class."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "the_corpus.build_doc2vec()\n",
+    "term_document_matrix = the_corpus.get_term_document_matrix()\n",
+    "print_matrix(\"Docs\", term_document_matrix)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Exercise 9 : corpus analysis using Cosine Similarity\n",
+    "Display the similarity between every pair of document.\n",
+    "Which movies are close to each other ? Which method works best ? Why ?"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "def corpus_analysis(corpus: DocCorpus, method: str) -> None:\n",
+    "    \"\"\"\n",
+    "    Calculate and display the cosine similarity between every pair of document for a given vectorization method\n",
+    "\n",
+    "    :param corpus: Corpus to analyse.\n",
+    "    :param method: Method to use for the analysis.\n",
+    "    \"\"\"\n",
+    "    print(\"\\n---- \" + method + \" ----\")\n",
+    "    corpus.set_method(method)\n",
+    "    corpus.build_vectors()\n",
+    "    matrix = corpus.get_term_document_matrix()\n",
+    "    \n",
+    "    # @COMPLETE : compute cosine similarity between every vector of the matrix\n",
+    "    # \n",
+    "    for i in range(0, len(corpus.docs) - 1):\n",
+    "        # Take a vector and build a two dimension matrix needed by cosine_similarity\n",
+    "        vec1 = matrix[i].reshape(1, -1)\n",
+    "\n",
+    "        for j in range(i + 1, len(corpus.docs)):\n",
+    "            # Take a vector and build a two dimension matrix needed by cosine_similarity\n",
+    "            vec2 = matrix[j].reshape(1, -1)\n",
+    "            \n",
+    "            # Retrieve name of the docs\n",
+    "            url_i = corpus.docs[i].url\n",
+    "            url_j = corpus.docs[j].url\n",
+    "\n",
+    "            # Compute and display the similarity\n",
+    "            print(\"\\tSim(doc\" + url_i + \",doc\" + url_j + \")=\" + \"{:.3f}\".format(cosine_similarity(vec1, vec2)[0, 0]))\n",
+    "\n",
+    "\n",
+    "# -----------------------------------------------------------------------------------------------------------\n",
+    "corpus_analysis(corpus=the_corpus, method=\"TF-IDF\")\n",
+    "corpus_analysis(corpus=the_corpus, method=\"Doc2Vec\")\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Web Mining",
+   "language": "python",
+   "name": "web-mining"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.9.9"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}