Compute p@10 using 0 == irrel, 1+ == rel, so that P@10 is in the expected range [0..1]

db/migrate/20240626181338_reindex_p_at10_code.rb

@@ -0,0 +1,12 @@
+class ReindexPAt10Code < ActiveRecord::Migration[7.1]
+  # force existing P@10 scorers to reload using the latest scorer information.
+  def change
+    scorers_to_update = ['P@10']
+    scorers_to_update.each do |scorer_name|
+      scorer = Scorer.where(name: scorer_name, communal: true).first
+      name = scorer.name
+      scorer.code = File.readlines("./db/scorers/#{name.downcase}.js",'\n').join('\n')
+      scorer.save!
+    end    
+  end
+end

db/scorers/p@10.js

@@ -1,4 +1,11 @@
-var k = 10 // @Rank
-var score = avgRating(k);
-
+const k = 10; // @Rank
+// k may be > length list, so count up the total number of documents processed.
+let count = 0, total = 0;
+eachDoc(function(doc, i) {
+    if (hasDocRating(i) && (docRating(i)) > 0) { // map 0 -> irrel, 1+ ->rel
+        count = count i+1
+    }
+    total = total + 1
+}, k);
+const score = count / total : 0.0;
 setScore(score);