Best price per square foot - PhillyDev Slack #daily_programmer - 201703

dp20170303.js

/*
Download the data file from:
https://github.com/aisflat439/dailyProgrammer/blob/master/data/realEstate.csv

0  street
1  city
2  zip
3  state
4  beds
5  baths
6  sq__ft
7  type
8  sale_date
9  price
10  latitude
11  longitude

*/

let fs = require('fs');
const fileName = process.argv[2];

let listings = readFile(fileName);

const minLat = listings.reduce(reduceMinLat, listings[0][10]);
const maxLat = listings.reduce(reduceMaxLat, listings[0][10]);
const minLng = listings.reduce(reduceMinLng, listings[0][11]);
const maxLng = listings.reduce(reduceMaxLng, listings[0][11]);

const midLat = (minLat + maxLat) / 2;
const midLng = (minLng + maxLng) / 2;

// Some listings have a price that is to low and must be the rental price.
// So I've decided that they should be omitted.
listings = listings.filter(minPrice);

const bestListing = {
  "overall": listings.reduce(bestPrice, listings[0]),
  "northern": listings.filter(isNorthern).reduce(bestPrice, listings[0]),
  "southern": listings.filter(isSouthern).reduce(bestPrice, listings[0]),
  "eatern": listings.filter(isEastern).reduce(bestPrice, listings[0]),
  "western": listings.filter(isWestern).reduce(bestPrice, listings[0]),
};

for(var key in bestListing) {
   bestListing[key] = addPricePerSqFoot(bestListing[key]);
}
console.log(bestListing);


function bestPrice(best, listing) {
  const oldPrice = pricePerSqFoot(best[9], best[6]);
  const newPrice = pricePerSqFoot(listing[9], listing[6]);
  return (oldPrice < newPrice) ? best : listing;
}

function pricePerSqFoot(price, squareFoot) {
  //return (squareFoot > 0) ? price / squareFoot : 0;
  return price / squareFoot;
}

function addPricePerSqFoot(listing) {
  listing[12] = pricePerSqFoot(listing[9], listing[6]);
  return listing;
}

function minPrice(listing) {
  return listing[9] > 9999;
}


function isNorthern(listing) {
  return listing[10] > midLat;
}

function isSouthern(listing) {
  return listing[10] < midLat;
}

function isEastern(listing) {
  return listing[11] > midLng;
}

function isWestern(listing) {
  return listing[11] < midLng;
}


function reduceMinLat(a, b) {
  return (a < b[10]) ? a : b[10];
}

function reduceMaxLat(a, b) {
  return (a > b[10]) ? a : b[10];
}

function reduceMinLng(a, b) {
  return (a < b[11]) ? a : b[11];
}

function reduceMaxLng(a, b) {
  return (a > b[11]) ? a : b[11];
}

function readFile(fileName) {
  let data;
  try {
    const text = fs.readFileSync(fileName, "utf8");
    data = text.split('\r');
    data = data.map(function(line) {
      line = line.split(',');
      // I need to use these columns as numbers and converting here to prevent problems elsewhere.
      line[9] = parseInt(line[9]);
      line[10] = parseFloat(line[10]);
      line[11] = parseFloat(line[11]);
      return line;
    });
    // Clean up data, remove header row and empty last line.
    data.shift();
    data.pop();
  } catch (e) {
    console.log("ERROR: file: " + fileName + " error: " + e.message);

    return false;
  }

  return data;
}