1 |
1 |
2 import CW7b._ |
2 import CW7b._ |
3 |
3 |
4 // first test |
4 val urban_recs = |
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5 Map("1" -> List("b", "a"), |
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6 "2" -> List("y", "x"), |
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7 "3" -> List("a", "c")) |
5 |
8 |
6 def urban_groupById(ratings: List[(String, String)], |
9 val urban_names = Map("a" -> "A", "b" -> "B", "c" -> "C", "x" -> "X", "y" -> "Y") |
7 m: Map[String, List[String]]) : Map[String, List[String]] = ratings match { |
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8 case Nil => m |
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9 case (id, mov) :: rest => { |
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10 val old_ratings = m.getOrElse (id, Nil) |
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11 val new_ratings = m + (id -> (mov :: old_ratings)) |
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12 urban_groupById(rest, new_ratings) |
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13 } |
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14 } |
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15 //def urban_groupById(ratings: List[(String, String)]) = |
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16 // ratings.groupBy(_._1).view.mapValues(_.map(_._2)).toMap |
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17 |
10 |
18 def urban_get_csv_file(name: String) : List[String] = { |
11 assert(most_recommended(urban_recs, urban_names).toSet == |
19 import io.Source |
12 Set(("A",2), ("B",1), ("C",1), ("X",1), ("Y",1))) |
20 import scala.util._ |
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21 val csv = Source.fromFile(name)("ISO-8859-1") |
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22 csv.mkString.split("\n").toList.drop(1) |
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23 } |
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24 |
13 |
25 def urban_process_ratings(lines: List[String]) : List[(String, String)] = { |
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26 for (cols <- lines.map(_.split(",").toList); |
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27 if (cols(2).toInt >= 4)) yield (cols(0), cols(1)) |
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28 } |
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29 |
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30 def urban_process_movies(lines: List[String]) : List[(String, String)] = { |
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31 for (cols <- lines.map(_.split(",").toList)) yield (cols(0), cols(1)) |
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32 } |
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33 |
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34 |
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35 val urban_good_ratings = urban_process_ratings(urban_get_csv_file("ratings.csv")) |
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36 val urban_movie_names = urban_process_movies(urban_get_csv_file("movies.csv")) |
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37 |
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38 val urban_movie_names_map = urban_movie_names.toMap |
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39 val urban_ratings_map = urban_groupById(urban_good_ratings, Map()) |
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40 //val urban_ratings_map = groupById(urban_good_ratings, Map()) |
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41 |
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42 val urban_ratings_map2 = for ((k, v) <- urban_ratings_map) yield (k, v.take(2)) |
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43 |
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44 assert(most_recommended(urban_ratings_map2, urban_movie_names_map).take(3) == |
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45 List(("M*A*S*H (a.k.a. MASH) (1970)",15), |
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46 ("Star Trek: First Contact (1996)",10), |
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47 ("Inception (2010)",9))) |
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48 |
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