Ranking methods: Difference between revisions

</pre>

=={{header|Wren}}==

{{trans|Kotlin}}

{{libheader|Wren-math}}

{{libheader|Wren-fmt}}

<lang ecmascript>import "/math" for Nums

import "/fmt" for Fmt

/* all ranking functions assume the array of Pairs is non-empty and already sorted

by decreasing order of scores and then, if the scores are equal, by reverse

alphabetic order of names

*/

var standardRanking = Fn.new { |scores|

var rankings = List.filled(scores.count, 0)

rankings[0] = 1

for (i in 1...scores.count) {

rankings[i] = (scores[i][0] == scores[i-1][0]) ? rankings[i-1] : i + 1

}

return rankings

}

var modifiedRanking = Fn.new { |scores|

var rankings = List.filled(scores.count, 0)

rankings[0] = 1

for (i in 1...scores.count) {

rankings[i] = i + 1

var currScore = scores[i][0]

for (j in i-1..0) {

if (currScore != scores[j][0]) break

rankings[j] = i + 1

}

}

return rankings

}

var denseRanking = Fn.new { |scores|

var rankings = List.filled(scores.count, 0)

rankings[0] = 1

var prevRanking = 1

for (i in 1...scores.count) {

rankings[i] = (scores[i][0] == scores[i-1][0]) ? prevRanking : (prevRanking = prevRanking+1)

}

return rankings

}

var ordinalRanking = Fn.new { |scores| (1..scores.count).toList }

var fractionalRanking = Fn.new { |scores|

var rankings = List.filled(scores.count, 0)

rankings[0] = 1

for (i in 1...scores.count) {

var k = i

var currScore = scores[i][0]

for (j in i-1..0) {

if (currScore != scores[j][0]) break

k = j

}

var avg = Nums.mean(k..i) + 1

for (m in k..i) rankings[m] = avg

}

return rankings

}

var printRankings = Fn.new { |title, rankings, scores|

System.print(title + ":")

for (i in 0...rankings.count) {

System.print("%(rankings[i]) %(scores[i][0]) %(scores[i][1])")

}

System.print()

}

var printFractionalRankings = Fn.new { |title, rankings, scores|

System.print(title + ":")

for (i in 0...rankings.count) {

Fmt.print("$3.2f $d $s", rankings[i], scores[i][0], scores[i][1])

}

System.print()

}

var scores = [[44, "Solomon"], [42, "Jason"], [42, "Errol"], [41, "Garry"],

[41, "Bernard"], [41, "Barry"], [39, "Stephen"]]

printRankings.call("Standard ranking", standardRanking.call(scores), scores)

printRankings.call("Modified ranking", modifiedRanking.call(scores), scores)

printRankings.call("Dense ranking", denseRanking.call(scores), scores)

printRankings.call("Ordinal ranking", ordinalRanking.call(scores), scores)

printFractionalRankings.call("Fractional ranking", fractionalRanking.call(scores), scores)</lang>

{{out}}

<pre>

Standard ranking:

1 44 Solomon

2 42 Jason

2 42 Errol

4 41 Garry

4 41 Bernard

4 41 Barry

7 39 Stephen

Modified ranking:

1 44 Solomon

3 42 Jason

3 42 Errol

6 41 Garry

6 41 Bernard

6 41 Barry

7 39 Stephen

Dense ranking:

1 44 Solomon

2 42 Jason

2 42 Errol

3 41 Garry

3 41 Bernard

3 41 Barry

4 39 Stephen

Ordinal ranking:

1 44 Solomon

2 42 Jason

3 42 Errol

4 41 Garry

5 41 Bernard

6 41 Barry

7 39 Stephen

Fractional ranking:

1.00 44 Solomon

2.50 42 Jason

2.50 42 Errol

5.00 41 Garry

5.00 41 Bernard

5.00 41 Barry

7.00 39 Stephen