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Perceptor: An artificially intelligent guided navigation system for WPF

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22 Mar 2009LGPL312 min read 177.5K   1.6K   217  
Knowledge acquired by a neural network is used to predict the element to which a user may intend to navigate.
using System;
using System.Collections.Generic;
using System.Linq;

using DanielVaughan.AI.NeuralNetworking;
using DanielVaughan.Tests.AI.NeuralNetworking;

using Microsoft.VisualStudio.TestTools.UnitTesting;

namespace DanielVaughan.Tests
{
	/// <summary>
    ///This is a test class for NeuralNetworkTest and is intended
    ///to contain all NeuralNetworkTest Unit Tests
    ///</summary>
	[TestClass]
	public class NeuralNetworkTest
	{
		const double high = .99;
		const double middle = .5;
		const double low = .01;

		/// <summary>
		///Gets or sets the test context which provides
		///information about and functionality for the current test run.
		///</summary>
		public TestContext TestContext { get; set; }

		#region Additional test attributes
		// 
		//You can use the following additional attributes as you write your tests:
		//
		//Use ClassInitialize to run code before running the first test in the class
		//[ClassInitialize()]
		//public static void MyClassInitialize(TestContext testContext)
		//{
		//}
		//
		//Use ClassCleanup to run code after all tests in a class have run
		//[ClassCleanup()]
		//public static void MyClassCleanup()
		//{
		//}
		//
		//Use TestInitialize to run code before running each test
		//[TestInitialize()]
		//public void MyTestInitialize()
		//{
		//}
		//
		//Use TestCleanup to run code after each test has run
		//[TestCleanup()]
		//public void MyTestCleanup()
		//{
		//}
		//
		#endregion


		/// <summary>
		///A test for Train
		///</summary>
		[TestMethod]
		public void TrainShouldBuildNetworkForXor()
		{
			double lowLow, lowHigh, highLow, highHigh;

			double[][] input = new [] { new[] { high, high }, new[] { low, high }, new[] { high, low }, new[] { low, low }};
			double[][] expectedOutput = new [] {new[] {low}, new[] {high}, new[] {high}, new[] {low}};

			var trainingSet = new TrainingSet(new List<LayerStimulus>
			                                  	{
			                                  		new LayerStimulus(new[] { high, high }), 
													new LayerStimulus(new[] { low, high }), 
													new LayerStimulus(new[] { high, low }), 
													new LayerStimulus(new[] { low, low })
			                                  	},
												new List<LayerStimulus> { 
													new LayerStimulus(new[] { low }), 
													new LayerStimulus(new[] { high }), 
													new LayerStimulus(new[] { high }), 
													new LayerStimulus(new[] { low }) 
												});

			var target = new NeuralNetwork(2, 2, 1);

			int iterations = 50;
			int count = 0;

			do
			{
				count++;

				target.Train(trainingSet, iterations);

				target.SetInputValue(0, false);
				target.SetInputValue(1, false);

				target.Pulse();

				lowLow = target.GetOutputValue(0);

				target.SetInputValue(0, true);
				target.SetInputValue(1, false);

				target.Pulse();

				highLow = target.GetOutputValue(0);

				target.SetInputValue(0, false);
				target.SetInputValue(1, true);

				target.Pulse();

				lowHigh = target.GetOutputValue(0);

				target.SetInputValue(0, true);
				target.SetInputValue(1, true);

				target.Pulse();

				highHigh = target.GetOutputValue(0);

			} while (count < 90001 && 
				(highHigh > (middle + low) / 2
				|| lowHigh < (middle + high) / 2
				|| highLow < (middle + low) / 2
				|| lowLow > (middle + high) / 2));

			Assert.IsTrue(count < 90000, "Number of iterations exceeded expected value.");
		}

		readonly bool[][] xorBoolInput = new[] { new[] { true, true }, new[] { false, true }, new[] { true, false }, new[] { false, false } };
		readonly bool[][] xorBoolOutput = new[] { new[] { false }, new[] { true }, new[] { true }, new[] { false } };

		/// <summary>
		///A test for Train
		///</summary>
		[TestMethod]
		public void TrainShouldBuildNetworkForXorBool()
		{
			bool falseFalse, falseTrue, trueFalse, trueTrue;

			var input = xorBoolInput;
			var expectedOutput = xorBoolOutput;

			var target = new NeuralNetwork(2, 2, 1) { LearningRate = 3 };

			int iterations = 5;
			target.Train(input, expectedOutput, iterations);
			int count = 0;

			do
			{
				count++;

				target.Train(input, expectedOutput, iterations);

				target.InputAsBooleans = new[] {false, false};
				target.Pulse();
				falseFalse = target[0];

				target.InputAsBooleans = new[] { true, false };
				target.Pulse();
				trueFalse = target[0];

				target.InputAsBooleans = new[] { false, true };
				target.Pulse();
				falseTrue = target[0];

				target.InputAsBooleans = new[] { true, true };
				target.Pulse();
				trueTrue = target[0];

			} while (count < 90001 &&
				(trueTrue
				|| !falseTrue
				|| !trueFalse
				|| falseFalse));

			Assert.IsTrue(count < 90000, "Number of iterations exceeded expected value.");
		}

		/// <summary>
		///A test for MeasureAccuracy
		///</summary>
		[TestMethod]
		public void MeasureAccuracyShouldReturnALowResultBeforeTraining()
		{
			var input = xorBoolInput;
			var expectedOutput = xorBoolOutput;

			var target = new NeuralNetwork(2, 2, 1) { LearningRate = 3 };

			double accuracy = target.MeasureAccuracy(input, expectedOutput);
			/* Accuracy should be around 50% because we haven't trained it yet. */
			double expectedAccuracy = .6;
			Assert.IsTrue(accuracy < expectedAccuracy, "Expected accuracy to be less than "
				+ expectedAccuracy + " but it was " + accuracy);
		}

		/// <summary>
		///A test for MeasureAccuracy
		///</summary>
		[TestMethod]
		public void MeasureAccuracyShouldReturnAHighResultAfterTraining()
		{
			var input = xorBoolInput;
			var expectedOutput = xorBoolOutput;

			var target = new NeuralNetwork(2, 2, 1);
			int iterations = 5000;
			target.Train(input, expectedOutput, iterations);
			double accuracy = target.MeasureAccuracy();
			double expectedAccuracy = .5;
			Assert.IsTrue(accuracy > expectedAccuracy, "Expected accuracy to be greater than "
				+ expectedAccuracy + " but it was " + accuracy);

			target.Train(input, expectedOutput, iterations);
			accuracy = target.MeasureAccuracy();
			expectedAccuracy = .7;
			Assert.IsTrue(accuracy > expectedAccuracy, "Expected accuracy to be greater than "
				+ expectedAccuracy + " but it was " + accuracy);

			target.Train(input, expectedOutput, iterations);
			accuracy = target.MeasureAccuracy();
			expectedAccuracy = .7;
			Assert.IsTrue(accuracy > expectedAccuracy, "Expected accuracy to be greater than "
				+ expectedAccuracy + " but it was " + accuracy);
		}

		[TestMethod]
		public void TrainShouldTimeoutIfAccuracyNotReached()
		{
			var input = xorBoolInput;
			var expectedOutput = xorBoolOutput;

			var target = new NeuralNetwork(2, 2, 1);
			var timedTrainingResult = target.Train(input, expectedOutput, 1, 1);
			Assert.AreEqual(TrainingResult.RanOutOfTime, timedTrainingResult.TrainingResult);
			Assert.IsTrue(timedTrainingResult.AccuracyAttained < 1, "Accuracy obtained should be less than 1.");

			target = new NeuralNetwork(2, 2, 1);
			timedTrainingResult = target.Train(input, expectedOutput, 1, 1000);
			Assert.AreEqual(TrainingResult.RanOutOfTime, timedTrainingResult.TrainingResult);
			Assert.IsTrue(timedTrainingResult.AccuracyAttained < 1, "Accuracy obtained should be less than 1.");
		}

		[TestMethod]
		public void TrainShouldNotTimeoutIfAccuracyReached()
		{
			var input = xorBoolInput;
			var expectedOutput = xorBoolOutput;

			var target = new NeuralNetwork(2, 2, 1);
			double soughtAccuracy = .01;
			var timedTrainingResult = target.Train(input, expectedOutput, soughtAccuracy, 100);
			string message = string.Format("Accuracy obtained should be greater than {0}, but was only {1}.",
										   soughtAccuracy, timedTrainingResult.AccuracyAttained);
			Assert.AreEqual(TrainingResult.Success, timedTrainingResult.TrainingResult, message);
			Assert.IsTrue(timedTrainingResult.AccuracyAttained > soughtAccuracy, message);

			target = new NeuralNetwork(2, 2, 1);
			soughtAccuracy = .7;
			timedTrainingResult = target.Train(input, expectedOutput, soughtAccuracy, 1000);
			message = string.Format("Accuracy obtained should be greater than {0}, but was only {1}.",
			                               soughtAccuracy, timedTrainingResult.AccuracyAttained);
			Assert.AreEqual(TrainingResult.Success, timedTrainingResult.TrainingResult, message);
			Assert.IsTrue(timedTrainingResult.AccuracyAttained > soughtAccuracy, message);

			soughtAccuracy = .72;
			timedTrainingResult = target.Train(input, expectedOutput, soughtAccuracy, 10000);
			message = string.Format("Accuracy obtained should be greater than {0}, but was only {1}.",
										   soughtAccuracy, timedTrainingResult.AccuracyAttained);
			Assert.AreEqual(TrainingResult.Success, timedTrainingResult.TrainingResult, message);
			Assert.IsTrue(timedTrainingResult.AccuracyAttained > soughtAccuracy, message);
		}

		[TestMethod]
		public void TrainShouldCorrectlyTrainForOneOutput()
		{
			var inputNeuronCount = 5;
			var outputNeuronCount = 50;
			var hiddenNeuronCount = inputNeuronCount;
            
			var input = new double[inputNeuronCount];
			for (int i = 0; i < input.Length; i++)
			{
				input[i] = low;
			}

			var output = new double[outputNeuronCount];
			for (int i = 0; i < output.Length; i++)
			{
				output[i] = low;
			}

			var neuralNetwork = new NeuralNetwork(inputNeuronCount, hiddenNeuronCount, outputNeuronCount);
			neuralNetwork.Input = input;
			neuralNetwork.Pulse();
			var toto = neuralNetwork.Output;

			output[0] = high;
			var trainingSet = new TrainingSet(new List<LayerStimulus> { new LayerStimulus(input) },
											  new List<LayerStimulus> { new LayerStimulus(output) });
			neuralNetwork.Train(trainingSet, 500);

			neuralNetwork.Input = input;
			neuralNetwork.Pulse();
			toto = neuralNetwork.Output;
			var indexOfHighest = NeuralNetworkTimeSeries.GetIndexOfHighest(toto);
			Assert.AreEqual(0, indexOfHighest);
		}

		[TestMethod]
		public void TrainShouldLearnCorrectlyOnRepeatTraining()
		{
			var neuralNetwork = new NeuralNetwork(4, 4, 4);
			int trainingIterations = 1000;
			var input = new[] {low, high, low, high};
			var output = new [] {low, low, low, high};

			var trainingSet = new TrainingSet(new List<LayerStimulus> {new LayerStimulus(input)},
			                                  new List<LayerStimulus> {new LayerStimulus(output)});
			neuralNetwork.Train(trainingSet, trainingIterations);
			neuralNetwork.Input = new [] {low, high, low, high};
			neuralNetwork.Pulse();
			var actualOutput = neuralNetwork.Output.ToList();
			var indexOfHighest = NeuralNetworkTimeSeries.GetIndexOfHighest(actualOutput);
			Assert.AreEqual(3, indexOfHighest);

			input = new[] { low, high, high, high };
			output = new[] { low, low, high, low };
			trainingSet = new TrainingSet(new List<LayerStimulus> { new LayerStimulus(input) },
											  new List<LayerStimulus> { new LayerStimulus(output) });
			neuralNetwork.Train(trainingSet, trainingIterations);
			neuralNetwork.Input = input;
			neuralNetwork.Pulse();
			actualOutput = neuralNetwork.Output.ToList();
			indexOfHighest = NeuralNetworkTimeSeries.GetIndexOfHighest(actualOutput);
			Assert.AreEqual(2, indexOfHighest);

			input = new[] { low, high, low, high };
			output = new[] { low, low, low, high };
			trainingSet = new TrainingSet(new List<LayerStimulus> { new LayerStimulus(input) },
											  new List<LayerStimulus> { new LayerStimulus(output) });
			neuralNetwork.Train(trainingSet, trainingIterations);
			neuralNetwork.Input = new[] { low, high, low, high };
			neuralNetwork.Pulse();
			actualOutput = neuralNetwork.Output.ToList();
			indexOfHighest = NeuralNetworkTimeSeries.GetIndexOfHighest(actualOutput);
			Assert.AreEqual(3, indexOfHighest);

			input = new[] { low, high, high, high };
			output = new[] { low, low, high, low };
			trainingSet = new TrainingSet(new List<LayerStimulus> { new LayerStimulus(input) },
											  new List<LayerStimulus> { new LayerStimulus(output) });

			neuralNetwork.Train(trainingSet, trainingIterations);
			neuralNetwork.Input = input;
			neuralNetwork.Pulse();
			actualOutput = neuralNetwork.Output.ToList();
			indexOfHighest = NeuralNetworkTimeSeries.GetIndexOfHighest(actualOutput);
			Assert.AreEqual(2, indexOfHighest);
            
			neuralNetwork.Input = new[] { low, high, low, high };
			neuralNetwork.Pulse();
			actualOutput = neuralNetwork.Output.ToList();
			indexOfHighest = NeuralNetworkTimeSeries.GetIndexOfHighest(actualOutput);
			Assert.AreEqual(3, indexOfHighest, string.Format(
				"Output: {0}, {1}, {2}, {3}", actualOutput[0], actualOutput[1], actualOutput[2], actualOutput[3]));
		}
	}
}

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License

This article, along with any associated source code and files, is licensed under The GNU Lesser General Public License (LGPLv3)


Written By
Engineer
Switzerland Switzerland
Daniel is a former senior engineer in Technology and Research at the Office of the CTO at Microsoft, working on next generation systems.

Previously Daniel was a nine-time Microsoft MVP and co-founder of Outcoder, a Swiss software and consulting company.

Daniel is the author of Windows Phone 8 Unleashed and Windows Phone 7.5 Unleashed, both published by SAMS.

Daniel is the developer behind several acclaimed mobile apps including Surfy Browser for Android and Windows Phone. Daniel is the creator of a number of popular open-source projects, most notably Codon.

Would you like Daniel to bring value to your organisation? Please contact

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