private static void Main()
{
try
{
Console.WriteLine("\nBegin neural network classification demo\n");
Console.WriteLine("Goal is to predict/classify color based on four numeric inputs\n");
_rnd = new Random(159); // 159 makes 'good' output
Console.WriteLine("Creating 100 lines of raw data");
string dataFile = "..\\..\\colors.txt";
MakeData(dataFile, 100);
Console.WriteLine("\nFirst few rows of raw data file are:");
Helpers.ShowTextFile(dataFile, 4);
double[][] trainMatrix;
double[][] testMatrix;
Console.WriteLine("\nGenerating train and test matrices using an 80%-20% split");
MakeTrainAndTest(dataFile, out trainMatrix, out testMatrix);
Console.WriteLine("\nFirst few rows of training matrix are:");
Helpers.ShowMatrix(trainMatrix, 5);
Console.WriteLine("\nCreating 4-input 5-hidden 3-output neural network");
var nn = new NeuralNetwork(4, 5, 3);
Console.WriteLine("Training to find best neural network weights using PSO with cross entropy error");
double[] bestWeights = nn.Train(trainMatrix);
Console.WriteLine("\nBest weights found:");
Helpers.ShowVector(bestWeights, 2, true);
Console.WriteLine("\nLoading best weights into neural network");
nn.SetWeights(bestWeights);
Console.WriteLine("\nAnalyzing the neural network accuracy on the test data\n");
double accuracy = nn.Test(testMatrix);
Console.WriteLine("Prediction accuracy = " + accuracy.ToString("F4"));
Console.WriteLine("\nEnd neural network classification demo\n");
Console.ReadLine();
}
catch (Exception ex)
{
Console.WriteLine("Fatal: " + ex.Message);
Console.ReadLine();
}
}
// Main()
// --------------------------------------------------------------------------------------------
private static void MakeData(string dataFile, int numLines)
{
var weights = new[]
{
-0.1, 0.2, -0.3, 0.4, -0.5,
0.6, -0.7, 0.8, -0.9, 1.0,
-1.1, 1.2, -1.3, 1.4, -1.5,
1.6, -1.7, 1.8, -1.9, 2.0,
-0.5, 0.6, -0.7, 0.8, -0.9,
1.5, -1.4, 1.3,
-1.2, 1.1, -1.0,
0.9, -0.8, 0.7,
-0.6, 0.5, -0.4,
0.3, -0.2, 0.1,
0.1, -0.3, 0.6
};
var nn = new NeuralNetwork(4, 5, 3);
nn.SetWeights(weights);
var ofs = new FileStream(dataFile, FileMode.Create);
var sw = new StreamWriter(ofs);
for (int i = 0; i < numLines; ++i)
{
var inputs = new double[4];
for (int j = 0; j < inputs.Length; ++j)
inputs[j] = _rnd.Next(1, 10);
double[] outputs = nn.ComputeOutputs(inputs);
string color = "";
int idx = Helpers.IndexOfLargest(outputs);
if (idx == 0)
{
color = "red";
}
else if (idx == 1)
{
color = "green";
}
else if (idx == 2)
{
color = "blue";
}
sw.WriteLine(inputs[0].ToString("F1") + " " + inputs[1].ToString("F1") + " " + inputs[2].ToString("F1") +
" " + inputs[3].ToString("F1") + " " + color);
}
sw.Close();
ofs.Close();
}