Merge pull request #355 from Ashutosh-Kumar-Singh-IIT-Patna/bleu-scor…

…e-metric

Bleu score metric

src/widgets/MetricsWidget/metrics.ts

@@ -2,6 +2,7 @@ import _ from 'lodash';
 import levenshtein from 'fast-levenshtein';
 import { Metric } from './types';
 import { computeConfusion } from './confusion';
+import { bleu } from 'bleu-score';
 import rouge from 'rouge';
 
 export const METRICS: Record<string, Metric> = {
@@ -99,6 +100,24 @@ export const METRICS: Record<string, Metric> = {
             );
         },
     },
+    BLEU1: {
+        signature: {
+            X: ['str'],
+            Y: ['str'],
+        },
+        compute: ([actualValues, assignedValues]) => {
+            const scores = [];
+
+            for (let i = 0; i < actualValues.length; i++) {
+                const references = actualValues[i];
+                const candidate = assignedValues[i];
+                scores.push(bleu(references as string, candidate as string, 1));
+            }
+
+            const mean_bleu_score = _.mean(scores);
+            return mean_bleu_score;
+        },
+    },
     ROUGE1: {
         signature: {
             X: 'str',