Inheritance: IActivationFunction
Example #1
0
        public NetworkContainer CreateNetworkContainer()
        {
            NetworkContainer neuralNetwork = null;

            int[] hiddenLayers = new int[cbHiddenLayerNumber.SelectedIndex];

            switch (hiddenLayers.Length)
            {
                case 0:
                    break;
                case 1:
                    hiddenLayers[0] = (int)this.nHidden1.Value;
                    break;
                case 2:
                    hiddenLayers[1] = (int)this.nHidden2.Value;
                    goto case 1;
                case 3:
                    hiddenLayers[2] = (int)this.nHidden3.Value;
                    goto case 2;
                case 4:
                    hiddenLayers[3] = (int)this.nHidden4.Value;
                    goto case 3;
                default:
                    break;
            }

            IActivationFunction activationFunction = null;

            if (this.rbBipolarSigmoid.Checked)
            {
                activationFunction = new BipolarSigmoidFunction((double)numSigmoidAlpha.Value);
            }
            else if (this.rbSigmoid.Checked)
            {
                activationFunction = new SigmoidFunction((double)numSigmoidAlpha.Value);
            }
            else if (this.rbThreshold.Checked)
            {
                activationFunction = new ThresholdFunction();
            }

            neuralNetwork = new NetworkContainer(
                    tbNetworkName.Text,
                    m_networkSchema,
                    activationFunction,
                    hiddenLayers);

             //         neuralNetwork.Schema.DataRanges.ActivationFunctionRange = new AForge.DoubleRange((double)numRangeLow.Value, (double)numRangeHigh.Value);

            return neuralNetwork;
        }
Example #2
0
        private static void network(double[][] inputs, int[] outputs)
        {
            // Since we would like to learn binary outputs in the form
            // [-1,+1], we can use a bipolar sigmoid activation function
            IActivationFunction function = new BipolarSigmoidFunction();

            // In our problem, we have 2 inputs (x, y pairs), and we will 
            // be creating a network with 5 hidden neurons and 1 output:
            //
            var network = new ActivationNetwork(function,
                inputsCount: 2, neuronsCount: new[] { 5, 1 });

            // Create a Levenberg-Marquardt algorithm
            var teacher = new LevenbergMarquardtLearning(network)
            {
                UseRegularization = true
            };


            // Because the network is expecting multiple outputs,
            // we have to convert our single variable into arrays
            //
            var y = outputs.ToDouble().ToArray();

            // Iterate until stop criteria is met
            double error = double.PositiveInfinity;
            double previous;

            do
            {
                previous = error;

                // Compute one learning iteration
                error = teacher.RunEpoch(inputs, y);

            } while (Math.Abs(previous - error) < 1e-10 * previous);


            // Classify the samples using the model
            int[] answers = inputs.Apply(network.Compute).GetColumn(0).Apply(System.Math.Sign);

            // Plot the results
            ScatterplotBox.Show("Expected results", inputs, outputs);
            ScatterplotBox.Show("Network results", inputs, answers)
                .Hold();
        }
Example #3
0
        /// <summary>
        /// Background worker for neural network learning
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void backgroundWorkerNeural_DoWork(object sender, DoWorkEventArgs e)
        {
            string connectionString = "Data Source=192.168.0.245;Initial Catalog=MyDB;Integrated Security=True; Connection Timeout=30000";// +
               using (SqlConnection connection = new SqlConnection(connectionString))
               {
               try
               {
                   connection.Open();
                   string queryString = "SELECT * FROM rates WHERE [i1]<>0 AND [i2]<>0 AND [i3]<>0 AND [i4]<>0 AND [i5]<>0 AND [i6]<>0 AND [i7]<>0 AND [i8]<>0" +
                                         " AND [i9]<>0 AND [i10]<>0 AND [i11]<>0 AND [i12]<>0 AND [i13]<>0 AND [i14]<>0 AND [i15]<>0 AND [i16]<>0" +
                                         " AND [i17]<>0 AND [i18]<>0 AND [i20]<>0 AND [i21]<>0 AND [i23]<>0";
                   SqlCommand command = new SqlCommand(queryString, connection);
                   SqlDataReader reader = command.ExecuteReader();

                   DataTable dt = new DataTable();
                   dt.Load(reader);
                   int value_count = dt.Rows.Count;
                   double[][] input_arr = new double[value_count][];
                   double[][] output_arr = new double[value_count][];
                   for (int j = 0; j < value_count; j++)
                   {
                       input_arr[j] = new double[21];
                       output_arr[j] = new double[1];
                   }
                   // Call Read before accessing data.

                   for (int i = 0; i < value_count; i++)
                   {
                       DataRow row = dt.Rows[i];
                       input_arr[i][0] = Double.Parse(row["i1"].ToString());
                       input_arr[i][1] = Double.Parse(row["i2"].ToString());
                       input_arr[i][2] = Double.Parse(row["i3"].ToString());
                       input_arr[i][3] = Double.Parse(row["i4"].ToString());
                       input_arr[i][4] = Double.Parse(row["i5"].ToString());
                       input_arr[i][5] = Double.Parse(row["i6"].ToString());
                       input_arr[i][6] = Double.Parse(row["i7"].ToString());
                       input_arr[i][7] = Double.Parse(row["i8"].ToString());
                       input_arr[i][8] = Double.Parse(row["i9"].ToString());
                       input_arr[i][9] = Double.Parse(row["i10"].ToString());
                       input_arr[i][10] = Double.Parse(row["i11"].ToString());
                       input_arr[i][11] = Double.Parse(row["i12"].ToString());
                       input_arr[i][12] = Double.Parse(row["i13"].ToString());
                       input_arr[i][13] = Double.Parse(row["i14"].ToString());
                       input_arr[i][14] = Double.Parse(row["i15"].ToString());
                       input_arr[i][15] = Double.Parse(row["i16"].ToString());
                       input_arr[i][16] = Double.Parse(row["i17"].ToString());
                       input_arr[i][17] = Double.Parse(row["i18"].ToString());
                       input_arr[i][18] = Double.Parse(row["i20"].ToString());
                       input_arr[i][19] = Double.Parse(row["i21"].ToString());
                       input_arr[i][20] = Double.Parse(row["i23"].ToString());
                       //output_arr[i][0] = Double.Parse(row["Difference"].ToString());
                       if (Double.Parse(row["Difference"].ToString()) > 0)
                           output_arr[i][0] = 1;
                       else if (Double.Parse(row["Difference"].ToString()) == 0)
                           output_arr[i][0] = 0;
                       else
                           output_arr[i][0] = -1;
                   }
                   int[] neurons = new int[5] { 21, 21, 21, 21, 1 };
                   AForge.Neuro.BipolarSigmoidFunction sigmoiddFunction = new AForge.Neuro.BipolarSigmoidFunction();
                   //AForge.Neuro.SigmoidFunction sigmoiddFunction = new AForge.Neuro.SigmoidFunction(2);
                   AForge.Neuro.ActivationNetwork network = new AForge.Neuro.ActivationNetwork(sigmoiddFunction, 21, 1);
                   AForge.Neuro.ActivationNetwork network1 = new AForge.Neuro.ActivationNetwork(sigmoiddFunction, 21, 1);//neurons);
                   //AForge.Neuro.Learning.DeltaRuleLearning teacher = new AForge.Neuro.Learning.DeltaRuleLearning(network) { LearningRate = 1};
                   AForge.Neuro.Learning.EvolutionaryLearning teacher = new AForge.Neuro.Learning.EvolutionaryLearning(network, 1000);
                   // AForge.Neuro.Learning.ResilientBackpropagationLearning teacher = new AForge.Neuro.Learning.ResilientBackpropagationLearning(network) { LearningRate = 1 };
                   //AForge.Neuro.Learning.PerceptronLearning teacherP = new PerceptronLearning(network1){ LearningRate =1};
                   //AForge.Neuro.Learning.BackPropagationLearning teacher = new AForge.Neuro.Learning.BackPropagationLearning(network) { LearningRate =1, Momentum = .2 };

                   // loop
                   bool noNeedToStop = false;
                   double error = 0;
                   //double error1 = 0;
                   double lastError = 0;
                   double learningRate = 1;
                   int k = 0;
                   sigmoiddFunction.Alpha = 0.01;
                   while (!noNeedToStop)
                   {
                       // run epoch of learning procedure
                       //error = teacher.RunEpoch(input_arr, output_arr);
                       //error = teacherP.RunEpoch(input_arr,output_arr);
                       error = teacher.RunEpoch(input_arr, output_arr);
                       double temp = Math.Abs(lastError - error);
                       if (error < 30)
                           noNeedToStop = true;
                       else if (temp < 0.0000001)
                       {
                           lastError = error;
                           k++;
                           if (k > 1000)
                           {
                               network.Randomize();
                               k = 0;
                           }
                           learningRate /= 2;

                           //if (learningRate < 0.001)
                           // {
                           //   learningRate = 0.001;
                           //network.Randomize();
                           // noNeedToStop = true;
                           // }
                       }
                       else
                           lastError = error;
                       // teacherP.LearningRate = learningRate;
                   }
                   network.Save(@"E:\\neural");

               }
               catch (Exception ex)
               {
                   message += " Exception: " + ex.Message;
               }
               finally
               {
                   connection.Close();
               }
               }
        }
        private static NeuralNetworkEvaluator evaluateSingleLayerActivationNetworkWithSigmoidFunctionBackPropagationLearning(
            double[][] input, double[][] output, double[][] crossValidationInput, char[] crossValidationDataLabels,
            double[][] evaluationInput, char[] evaluationDataLabels, double learningRate, string networkName)
        {
            //Create the neural Network
            BipolarSigmoidFunction sigmoidFunction = new BipolarSigmoidFunction(2.0f);
            ActivationNetwork neuralNet = new ActivationNetwork(sigmoidFunction, input[0].Length, ClassifierHelpers.NUM_CHAR_CLASSES);

            //Randomise the networks initial weights
            neuralNet.Randomize();

            //Create teacher that the network will use to learn the data (Back Propogation Learning technique used here)
            BackPropagationLearning teacher = new BackPropagationLearning(neuralNet);
            teacher.LearningRate = LEARNING_RATE;

            //Train the Network
            //trainNetwork(neuralNet, teacher, input, output, crossValidationInput, crossValidationDataLabels);
            //Train multiple networks, pick the one that performs best on the Cross-Validation data
            neuralNet = trainNetworksCompeteOnCrossValidation(neuralNet, teacher,
                input, output, crossValidationInput, crossValidationDataLabels);

            //Evaluate the network returned on the cross-validation data so it can be compared to the current best
            NeuralNetworkEvaluator crossValEvaluator = new NeuralNetworkEvaluator(neuralNet);
            crossValEvaluator.Evaluate(crossValidationInput, crossValidationDataLabels);

            //See if this network is better than the current best network of it's type
            //Try and load a previous network of this type
            string previousNetworkPath = Program.NEURAL_NETWORKS_PATH + networkName + Program.NEURAL_NETWORK_FILE_EXTENSION;
            string networkCMPath = Program.NEURAL_NETWORKS_PATH + networkName + ".csv";
            bool newBest = false;
            ActivationNetwork bestNetwork = neuralNet;
            if(File.Exists(previousNetworkPath))
            {
                //Load the previous network & evaluate it
                ActivationNetwork previous = ActivationNetwork.Load(previousNetworkPath) as ActivationNetwork;
                NeuralNetworkEvaluator prevCrossValEval = new NeuralNetworkEvaluator(previous);
                prevCrossValEval.Evaluate(crossValidationInput, crossValidationDataLabels);

                //If this network is better than the previous best, write it out as the new best
                if(prevCrossValEval.ConfusionMatrix.NumMisclassifications > crossValEvaluator.ConfusionMatrix.NumMisclassifications)
                {
                    DefaultLog.Info("New best cross-validation score for network \"{0}\". Previous was {1}/{2}, new best is {3}/{2}",
                        networkName, prevCrossValEval.ConfusionMatrix.NumMisclassifications, prevCrossValEval.ConfusionMatrix.TotalClassifications,
                        crossValEvaluator.ConfusionMatrix.NumMisclassifications);

                    //Delete the old files
                    File.Delete(previousNetworkPath);
                    File.Delete(networkCMPath);

                    newBest = true;
                }
                else //The previous network is still the best
                {
                    DefaultLog.Info("Existing \"{0}\" network performed better than new one. New network scored {1}/{2}, existing scored {3}/{2}",
                        networkName, crossValEvaluator.ConfusionMatrix.NumMisclassifications, crossValEvaluator.ConfusionMatrix.TotalClassifications,
                        prevCrossValEval.ConfusionMatrix.NumMisclassifications);
                    bestNetwork = previous;
                }
            }
            else //Otherwise there isn't a previous best
            {
                DefaultLog.Info("No previous best record for network \"{0}\" . . .", networkName);
                newBest = true;
            }

            //Evaluate the best system on the evaluation data
            NeuralNetworkEvaluator evaluator = new NeuralNetworkEvaluator(bestNetwork);
            evaluator.Evaluate(evaluationInput, evaluationDataLabels);

            //If there is a new best to write out
            if(newBest)
            {
                DefaultLog.Info("Writing out net best network of type\"{0}\"", networkName);
                neuralNet.Save(previousNetworkPath);

                //Write out the Confusion Matrix for the evaluation data, not cross-validation
                evaluator.ConfusionMatrix.WriteToCsv(networkCMPath);
                DefaultLog.Info("Finished writing out network \"{0}\"", networkName);
            }

            return evaluator;
        }