[clojure]: add comp-metric based on CompositeEvalMetric

contrib/clojure-package/src/org/apache/clojure_mxnet/eval_metric.clj

@@ -18,7 +18,7 @@
 (ns org.apache.clojure-mxnet.eval-metric
  (:refer-clojure :exclude [get update])
  (:require [org.apache.clojure-mxnet.util :as util])
- (:import (org.apache.mxnet Accuracy TopKAccuracy F1 Perplexity MAE MSE RMSE CustomMetric)))
+ (:import (org.apache.mxnet Accuracy TopKAccuracy F1 Perplexity MAE MSE RMSE CustomMetric CompositeEvalMetric)))
 
 (defn accuracy
  "Basic Accuracy Metric"
@@ -74,11 +74,21 @@
  [f-eval mname]
  `(new CustomMetric (util/scala-fn ~f-eval) ~mname))
 
+(defn comp-metric
+ "Create a metric instance composed out of several metrics"
+ [metrics]
+ (let [cm (CompositeEvalMetric.)]
+ (doseq [m metrics] (.add cm m))
+ cm))
+
 (defn get
- "Get the values of the metric in a vector form (name and value)"
+ "Get the values of the metric in as a map of {name value} pairs"
  [metric]
- (let [[[mname] [mvalue]] (util/tuple->vec (.get metric))]
- [mname mvalue]))
+ (let [m (apply zipmap (-> (.get metric)
+ util/tuple->vec))]
+ (if-not (instance? CompositeEvalMetric metric)
+ (first m)
+ m)))
 
 (defn reset
  "clear the internal statistics to an initial state"

contrib/clojure-package/test/org/apache/clojure_mxnet/eval_metric_test.clj

@@ -57,3 +57,12 @@
  "my-metric")]
  (eval-metric/update metric [(ndarray/ones [2])] [(ndarray/ones [2])])
  (is (= ["my-metric" 0.0] (eval-metric/get metric)))))
+
+(deftest test-comp-metric
+ (let [metric (eval-metric/comp-metric [(eval-metric/accuracy)
+ (eval-metric/f1)
+ (eval-metric/top-k-accuracy 2)])]
+ (eval-metric/update metric [(ndarray/ones [2])] [(ndarray/ones [2 3])])
+ (is (= {"accuracy" 0.0
+ "f1" 0.0
+ "top_k_accuracy" 1.0} (eval-metric/get metric)))))