September 2017 Update

Task/Ranking-methods/Kotlin/ranking-methods.kotlin

@@ -0,0 +1,80 @@
+// version 1.0.6
+
+/* 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
+*/
+
+fun standardRanking(scores: Array<Pair<Int, String>>): IntArray {
+    val rankings = IntArray(scores.size)
+    rankings[0] = 1
+    for (i in 1 until scores.size) rankings[i] = if (scores[i].first == scores[i - 1].first) rankings[i - 1] else i + 1
+    return rankings
+}
+
+fun modifiedRanking(scores: Array<Pair<Int, String>>): IntArray {
+    val rankings = IntArray(scores.size)
+    rankings[0] = 1
+    for (i in 1 until scores.size) {
+        rankings[i] = i + 1
+        val currScore = scores[i].first
+        for (j in i - 1 downTo 0) {
+            if (currScore != scores[j].first) break
+            rankings[j] = i + 1
+        }
+    }
+    return rankings
+}
+
+fun denseRanking(scores: Array<Pair<Int, String>>): IntArray {
+    val rankings = IntArray(scores.size)
+    rankings[0] = 1
+    var prevRanking = 1
+    for (i in 1 until scores.size) rankings[i] = if (scores[i].first == scores[i - 1].first) prevRanking else ++prevRanking
+    return rankings
+}
+
+fun ordinalRanking(scores: Array<Pair<Int, String>>) = IntArray(scores.size) { it + 1 }
+
+fun fractionalRanking(scores: Array<Pair<Int, String>>): DoubleArray {
+    val rankings = DoubleArray(scores.size)
+    rankings[0] = 1.0
+    for (i in 1 until scores.size) {
+        var k = i
+        val currScore = scores[i].first
+        for (j in i - 1 downTo 0) {
+            if (currScore != scores[j].first) break
+            k = j
+        }
+        val avg = (k..i).average() + 1.0
+        for (m in k..i) rankings[m] = avg
+    }
+    return rankings
+}
+
+fun printRankings(title: String, rankings: IntArray, scores: Array<Pair<Int, String>>) {
+    println(title + ":")
+    for (i in 0 until rankings.size) {
+        print ("${rankings[i]}  ")
+        println(scores[i].toString().removeSurrounding("(", ")").replace(",", ""))
+    }
+    println()
+}
+
+fun printFractionalRankings(title: String, rankings: DoubleArray, scores: Array<Pair<Int, String>>) {
+    println(title + ":")
+    for (i in 0 until rankings.size) {
+        print ("${"%3.2f".format(rankings[i])}  ")
+        println(scores[i].toString().removeSurrounding("(", ")").replace(",", ""))
+    }
+    println()
+}
+
+fun main(args: Array<String>) {
+    val scores = arrayOf(44 to "Solomon",  42 to "Jason", 42 to "Errol",  41 to "Garry",
+                         41 to "Bernard",  41 to "Barry", 39 to "Stephen")
+    printRankings("Standard ranking", standardRanking(scores), scores)
+    printRankings("Modified ranking", modifiedRanking(scores), scores)
+    printRankings("Dense ranking", denseRanking(scores), scores)
+    printRankings("Ordinal ranking", ordinalRanking(scores), scores)
+    printFractionalRankings("Fractional ranking", fractionalRanking(scores), scores)
+}

Task/Ranking-methods/Zkl/ranking-methods-1.zkl

@@ -0,0 +1,34 @@
+fcn group(scores){ // group like scores into one list --> list of lists
+   sink:=List();
+   scores.reduce('wrap(ps,sn,buf){
+      if(sn[0]!=ps){ sink.append(buf.copy()); buf.clear(); }
+      buf+sn;
+      sn[0];
+   },scores[0][0],buf:=List());
+   sink.append(buf);
+}
+fcn print(list,rank){
+   list.apply2('wrap(sn){ "%2s: %s (%d)".fmt(rank,sn[1],sn[0]):println(_); });
+}
+fcn rankViaStandard(scores){
+   rank:=1;
+   foreach group in (group(scores)){ print(group,rank); rank+=group.len(); }
+}
+fcn rankViaModified(scores){
+   rank:=0;
+   foreach group in (group(scores)){ rank+=group.len(); print(group,rank); }
+}
+fcn rankViaDense(scores){
+   rank:=1;
+   foreach group in (group(scores)){ print(group,rank); rank+=1; }
+}
+fcn rankViaOrdinal(scores){
+   scores.apply2('wrap(sn,rr){ "%2s: %s (%d)".fmt(rr.inc(),sn[1],sn[0]):println(_); },Ref(1));
+}
+fcn rankViaFractional(scores){
+   rank:=1;
+   foreach group in (group(scores)){
+      n:=group.len(); r:=rank.reduce(n,'+,0.0)/n; rank+=n;
+      print(group,"%5.2f".fmt(r));
+   }
+}

Task/Ranking-methods/Zkl/ranking-methods-2.zkl

@@ -0,0 +1,8 @@
+   // these are sorted!?!
+scores:=T(T(44,"Solomon"), T(42,"Jason"), T(42,"Errol"), T(41,"Garry"),
+        T(41,"Bernard"),T(41,"Barry"),T(39,"Stephen"),);
+"Standard:"  .println(); rankViaStandard(scores);
+"Modified:"  .println(); rankViaModified(scores);
+"Dense:"     .println(); rankViaDense(scores);
+"Ordinal:"   .println(); rankViaOrdinal(scores);
+"Fractional:".println(); rankViaFractional(scores);