ISOM3370 code

index.js

(async function() {

  let use_trim = true;
  let apriori = 0;
  
  // Filename
  let filename = [];
  if (apriori) {
    filename.push('apriori-' + apriori);
  }
  if (use_trim) {
    filename.push('trimmed');
  }
  let suffix = '';
  if (filename.length) {
    suffix = ' (' + filename.join(',') + ')';
  }

  // Functions
  let k_perm = function(arr) {
    return arr.reduce((set, record1, index1) => {
      arr.forEach((record2, index2) => {
        if (index1 !== index2) {
          set.push([record1, record2]);
        }
      });
      return set;
    }, []);
  };
  let k_perm_3 = function(arr) {
    return arr.reduce((set, record1, index1) => {
      arr.forEach((record2, index2) => {
        if (index1 < index2) {
          arr.forEach((record3, index3) => {
            if (index1 !== index3 && index2 !== index3) {
              set.push([record1, record2, record3]);
            }
          });
        }
      });
      return set;
    }, []);
  };

  let flatten = (obj) => {
    return Object.keys(obj).map(function(key) {
      return [key, obj[key]];
    });
  }
  let inflate = (arr) => {
    return arr.reduce((set, record) => { set[record[0]] = record[1]; return set}, {});
  };

  let dump = (object) => {
    let str = [];
    Object.keys(object).forEach((key) => {
      str.push('(' + key + ',[' + object[key].map((tuple) => tuple[0]).join(',') + '])');
    });
    return str.join("\n");
  };

  let start = new Date().getTime();

  // Load Data
  let url = 'https://cdn.rawgit.com/hfhchan/bcaaa02a8a1b13036a9d747ac749e6a4/raw/d08f8c3d19eac02b304dcdf7a76a99ea1ff9b046/browsing.txt';
  if (use_trim) {
    url = 'https://cdn.rawgit.com/hfhchan/57f3e3fed2da473ea434094b69c54c95/raw/42903230b31a580d9a3e3a8f366b7aa33d01079a/browsing-trim.txt';
  }

  let records = await fetch(url).then((response) => {
    return response.text();
  }).then(function (text) {
    let lines = text.trim().split("\n");
    return lines.map((line) => line.trim().split(" "));
  });


  // Part 1
  // Output popularity for each product
  // with product name as key and popularity as value
  let itemset1_1 = [];
  records.forEach((record) => {
    record.map((product) => {
      itemset1_1[product] = itemset1_1[product] || 0;
      itemset1_1[product] += 1;
    });
  });

  // Filter products with popularity over 100 and Sort by popularity
  let itemset1_2 = flatten(itemset1_1).filter((item) => item[1] >= apriori).sort((a,b) => {
    return b[1] - a[1];
  });
  itemset1_1 = null;

  // Cast into Correct Format
  let itemset1_3 = inflate(itemset1_2);
  itemset1_2 = null;
  console.log(itemset1_3);

  // Part 2
  // Output popularity of co-occurences of two products
  // with product names as key and occurences as value, with product names pre-filtered by the most popular items
  let itemset2_1 = [];
  records.forEach((record) => {
    let products = record.filter((product) => product in itemset1_3).sort();
    k_perm(products).map((product) => {
      product = product.join(' ');
      itemset2_1[product] = itemset2_1[product] || 0;
      itemset2_1[product] += 1;
    });
  });

  // Filter pairs with popularity over 100 and Sort by popularity
  let itemset2_2 = flatten(itemset2_1).filter((item) => item[1] >= apriori).sort((a,b) => {
    return b[1] - a[1];
  });

  // Output popularity of co-occurences of two products
  // with product name as key and tuples of co-occuring product and occurences as value
  let itemset2_3 = [];
  itemset2_2.forEach((record) => {
    let [product1, product2] = record[0].split(" ");
    itemset2_3[product1] = itemset2_3[product1] || [];
    itemset2_3[product1].push([product2, record[1] / itemset1_3[product1]]);
  });
  itemset2_2 = null;

  // Truncate to most popular 10
  // Object.keys(itemset2_3).forEach((key) => itemset2_3[key].length = itemset2_3[key].length > 10 ? 10 : itemset2_3[key].length );

  // Save to file
  var blobData = dump(itemset2_3);
  var myBlob = new Blob([blobData], {type: "plain/text"});
  blobURL = URL.createObjectURL(myBlob);
  var href = document.createElement("a");
  href.href = blobURL;
  href.download = 'Itemset 2' + suffix + '.txt';
  href.id = "download2"
  document.body.appendChild(href);
  document.getElementById("download2").click();

  // Part 3
  // Output popularity of co-occurences of three products
  // with product names as key and occurences as value, with product names pre-filtered by the most popular items
  let itemset3_1 = [];
  records.forEach((record) => {
    let products = record.filter((product) => product in itemset2_3).sort();
    k_perm_3(products).map((product) => {
      product = product.join(' ');
      itemset3_1[product] = itemset3_1[product] || 0;
      itemset3_1[product] += 1;
    });
  });

  // Sort the values
  let itemset3_2 = flatten(itemset3_1).sort((a,b) => {
    return b[1] - a[1];
  });
  itemset3_1 = null

  // Output popularity of co-occurences of three products
  // with two product names as key and tuples of co-occuring third product and occurences as value
  let itemset3_3 = [];
  itemset3_2.forEach((record) => {
    let [product1, product2, product3] = record[0].split(" ");
    let product1_2 = product1 + " " + product2;
    itemset3_3[product1_2] = itemset3_3[product1_2] || [];
    itemset3_3[product1_2].push([product3, record[1] / itemset2_1[product1_2]]);
  });
  itemset3_2 = null;

  // Truncate to most popular 10
  // Object.keys(itemset3_3).forEach((key) => itemset3_3[key].length = itemset3_3[key].length > 10 ? 10 : itemset3_3[key].length );


  // Save to file
  var blobData = dump(itemset3_3);
  var myBlob = new Blob([blobData], {type: "plain/text"});
  blobURL = URL.createObjectURL(myBlob);
  var href = document.createElement("a");
  href.href = blobURL;
  href.download = 'Itemset 3' + suffix + '.txt';
  href.id = "download3"
  document.body.appendChild(href);
  document.getElementById("download3").click();

  let end = new Date().getTime();
  console.log('Completed in ' + (end - start) + ' seconds.');
})();