def test_parameter_convergence(self):
        """Test that the model parameters improve with streaming data."""
        slr = StreamingLinearRegressionWithSGD(stepSize=0.2, numIterations=25)
        slr.setInitialWeights([0.0])

        # Create ten batches with 100 sample points in each.
        batches = []
        for i in range(10):
            batch = LinearDataGenerator.generateLinearInput(
                0.0, [10.0], [0.0], [1.0 / 3.0], 100, 42 + i, 0.1)
            batches.append(self.sc.parallelize(batch))

        model_weights = []
        input_stream = self.ssc.queueStream(batches)
        input_stream.foreachRDD(
            lambda x: model_weights.append(slr.latestModel().weights[0]))
        slr.trainOn(input_stream)
        self.ssc.start()

        def condition():
            self.assertEqual(len(model_weights), len(batches))
            return True

        # We want all batches to finish for this test.
        eventually(condition, 90, catch_assertions=True)

        w = array(model_weights)
        diff = w[1:] - w[:-1]
        self.assertTrue(all(diff >= -0.1))
    def test_parameter_convergence(self):
        """Test that the model parameters improve with streaming data."""
        slr = StreamingLinearRegressionWithSGD(stepSize=0.2, numIterations=25)
        slr.setInitialWeights([0.0])

        # Create ten batches with 100 sample points in each.
        batches = []
        for i in range(10):
            batch = LinearDataGenerator.generateLinearInput(
                0.0, [10.0], [0.0], [1.0 / 3.0], 100, 42 + i, 0.1)
            batches.append(self.sc.parallelize(batch))

        model_weights = []
        input_stream = self.ssc.queueStream(batches)
        input_stream.foreachRDD(
            lambda x: model_weights.append(slr.latestModel().weights[0]))
        slr.trainOn(input_stream)
        self.ssc.start()

        def condition():
            self.assertEqual(len(model_weights), len(batches))
            return True

        # We want all batches to finish for this test.
        self._eventually(condition, catch_assertions=True)

        w = array(model_weights)
        diff = w[1:] - w[:-1]
        self.assertTrue(all(diff >= -0.1))