Add winnow example test

test/classifiersTest/WinnowExampleTest.js

@@ -0,0 +1,55 @@
+var should = require('should');
+var limdu = require('../../index');
+
+// First, define our base classifier type (a multi-label classifier based on winnow):
+var TextClassifier = limdu.classifiers.multilabel.BinaryRelevance.bind(0, {
+	binaryClassifierType: limdu.classifiers.Winnow.bind(0, {retrain_count: 10})
+});
+
+// Define a feature extractor (a function that takes a sample and add features to a given features set):
+var WordExtractor = function(input, features) {
+	input.split(" ").forEach(function(word) {
+		features[word]=1;
+	});
+};
+
+describe('winnow classifier', function() {
+	it('works with a feature-extractor', function() {
+        // Initialize a classifier with a feature extractor:
+        var intentClassifier = new limdu.classifiers.EnhancedClassifier({
+            classifierType: TextClassifier,
+            featureExtractor: WordExtractor
+        });
+
+        // Train and test:
+        intentClassifier.trainBatch([
+            {input: "I want an apple", output: "apl"},
+            {input: "I want a banana", output: "bnn"},
+            {input: "I want chips", output: "cps"},
+            ]);
+        intentClassifier.classify("I want an apple and a banana").sort().should.eql(['apl','bnn']);
+        intentClassifier.classify("I WANT AN APPLE AND A BANANA").sort().should.eql([]);  // case sensitive
+	})
+})
+
+describe('winnow classifier', function() {
+	it('works with a case-normalizer', function() {
+
+        //Initialize a classifier with a feature extractor and a case normalizer:
+        intentClassifier = new limdu.classifiers.EnhancedClassifier({
+            classifierType: TextClassifier,
+            normalizer: limdu.features.LowerCaseNormalizer,
+            featureExtractor: WordExtractor
+        });
+
+        //Train and test:
+        intentClassifier.trainBatch([
+            {input: "I want an apple", output: "apl"},
+            {input: "I want a banana", output: "bnn"},
+            {input: "I want chips", output: "cps"},
+            ]);
+
+        intentClassifier.classify("I want an apple and a banana").sort().should.eql(['apl','bnn']);
+        intentClassifier.classify("I WANT AN APPLE AND A BANANA").sort().should.eql(['apl','bnn']); // case insensitive
+    })
+})