argmax NOW tiebreaks randomly

src/propeller/tools/metrics.cljc

@@ -1,13 +1,22 @@
 (ns propeller.tools.metrics
   (:require [propeller.tools.math :as math]))
 
-(defn argmax
-  "returns the index of the maximum value in a list"
+(defn argmax-last
+  "returns the index of the maximum value in a list, tiebreaking last"
   [coll]
   (->> coll
        (map-indexed vector)
        (apply max-key second)
-       rand-nth))
+       first))
+
+(defn argmax
+  "returns the index of the maximum value in a list, randomly tiebreaking"
+  [coll]
+  (->> coll
+       (map-indexed vector)
+       (filter #(= (apply max coll) (second %)))
+       rand-nth
+       first))
 
 (defn mean
   "Returns the mean of a collection."