示例#1
0
文件: Solver.cs 项目: wendelad/RecSys
        public static double svm_predict(Model model, Node[] x)
        {
            if (model.Parameter.SvmType == SvmType.ONE_CLASS ||
               model.Parameter.SvmType == SvmType.EPSILON_SVR ||
               model.Parameter.SvmType == SvmType.NU_SVR)
            {
                double[] res = new double[1];
                svm_predict_values(model, x, res);

                if (model.Parameter.SvmType == SvmType.ONE_CLASS)
                    return (res[0] > 0) ? 1 : -1;
                else
                    return res[0];
            }
            else
            {
                int i;
                int nr_class = model.NumberOfClasses;
                double[] dec_values = new double[nr_class * (nr_class - 1) / 2];
                svm_predict_values(model, x, dec_values);

                int[] vote = new int[nr_class];
                for (i = 0; i < nr_class; i++)
                    vote[i] = 0;
                int pos = 0;
                for (i = 0; i < nr_class; i++)
                    for (int j = i + 1; j < nr_class; j++)
                    {
                        if (dec_values[pos++] > 0)
                            ++vote[i];
                        else
                            ++vote[j];
                    }

                int vote_Max_idx = 0;
                for (i = 1; i < nr_class; i++)
                    if (vote[i] > vote[vote_Max_idx])
                        vote_Max_idx = i;
                return model.ClassLabels[vote_Max_idx];
            }
        }
示例#2
0
文件: Solver.cs 项目: wendelad/RecSys
        public static double svm_predict_probability(Model model, Node[] x, double[] prob_estimates)
        {
            if ((model.Parameter.SvmType == SvmType.C_SVC || model.Parameter.SvmType == SvmType.NU_SVC) &&
                model.PairwiseProbabilityA != null && model.PairwiseProbabilityB != null)
            {
                int i;
                int nr_class = model.NumberOfClasses;
                double[] dec_values = new double[nr_class * (nr_class - 1) / 2];
                svm_predict_values(model, x, dec_values);

                double Min_prob = 1e-7;
                double[,] pairwise_prob = new double[nr_class, nr_class];

                int k = 0;
                for (i = 0; i < nr_class; i++)
                {
                    for (int j = i + 1; j < nr_class; j++)
                    {
                        pairwise_prob[i, j] = Math.Min(Math.Max(sigmoid_predict(dec_values[k], model.PairwiseProbabilityA[k], model.PairwiseProbabilityB[k]), Min_prob), 1 - Min_prob);
                        pairwise_prob[j, i] = 1 - pairwise_prob[i, j];
                        k++;
                    }
                }
                multiclass_probability(nr_class, pairwise_prob, prob_estimates);

                int prob_Max_idx = 0;
                for (i = 1; i < nr_class; i++)
                    if (prob_estimates[i] > prob_estimates[prob_Max_idx])
                        prob_Max_idx = i;
                return model.ClassLabels[prob_Max_idx];
            }
            else
                return svm_predict(model, x);
        }
示例#3
0
文件: Solver.cs 项目: wendelad/RecSys
 public static SvmType svm_get_svm_type(Model model)
 {
     return model.Parameter.SvmType;
 }
示例#4
0
文件: Solver.cs 项目: wendelad/RecSys
 public static double svm_get_svr_probability(Model model)
 {
     if ((model.Parameter.SvmType == SvmType.EPSILON_SVR || model.Parameter.SvmType == SvmType.NU_SVR) &&
         model.PairwiseProbabilityA != null)
         return model.PairwiseProbabilityA[0];
     else
     {
         Console.Error.WriteLine("Model doesn't contain information for SVR probability inference");
         return 0;
     }
 }
示例#5
0
文件: Solver.cs 项目: wendelad/RecSys
 public static void svm_get_labels(Model model, int[] label)
 {
     if (model.ClassLabels != null)
         for (int i = 0; i < model.NumberOfClasses; i++)
             label[i] = model.ClassLabels[i];
 }
示例#6
0
文件: Solver.cs 项目: wendelad/RecSys
 public static int svm_get_nr_class(Model model)
 {
     return model.NumberOfClasses;
 }
示例#7
0
        /// <summary>
        /// Predicts the class memberships of all the vectors in the problem.
        /// </summary>
        /// <param name="problem">The SVM Problem to solve</param>
        /// <param name="outputFile">File for result output</param>
        /// <param name="model">The Model to use</param>
        /// <param name="predict_probability">Whether to output a distribution over the classes</param>
        /// <returns>Percentage correctly labelled</returns>
        public static double Predict(
            Problem problem,
            string outputFile,
            Model model,
            bool predict_probability)
        {
            int correct = 0;
            int total = 0;
            double error = 0;
            double sumv = 0, sumy = 0, sumvv = 0, sumyy = 0, sumvy = 0;
            StreamWriter output = outputFile != null ? new StreamWriter(outputFile) : null;

            SvmType svm_type = Procedures.svm_get_svm_type(model);
            int nr_class = Procedures.svm_get_nr_class(model);
            int[] labels = new int[nr_class];
            double[] prob_estimates = null;

            if (predict_probability)
            {
                if (svm_type == SvmType.EPSILON_SVR || svm_type == SvmType.NU_SVR)
                {
                    Console.WriteLine("Prob. model for test data: target value = predicted value + z,\nz: Laplace distribution e^(-|z|/sigma)/(2sigma),sigma=" + Procedures.svm_get_svr_probability(model));
                }
                else
                {
                    Procedures.svm_get_labels(model, labels);
                    prob_estimates = new double[nr_class];
                    if (output != null)
                    {
                        output.Write("labels");
                        for (int j = 0; j < nr_class; j++)
                        {
                            output.Write(" " + labels[j]);
                        }
                        output.Write("\n");
                    }
                }
            }
            for (int i = 0; i < problem.Count; i++)
            {
                double target = problem.Y[i];
                Node[] x = problem.X[i];

                double v;
                if (predict_probability && (svm_type == SvmType.C_SVC || svm_type == SvmType.NU_SVC))
                {
                    v = Procedures.svm_predict_probability(model, x, prob_estimates);
                    if (output != null)
                    {
                        output.Write(v + " ");
                        for (int j = 0; j < nr_class; j++)
                        {
                            output.Write(prob_estimates[j] + " ");
                        }
                        output.Write("\n");
                    }
                }
                else
                {
                    v = Procedures.svm_predict(model, x);
                    if(output != null)
                        output.Write(v + "\n");
                }

                if (v == target)
                    ++correct;
                error += (v - target) * (v - target);
                sumv += v;
                sumy += target;
                sumvv += v * v;
                sumyy += target * target;
                sumvy += v * target;
                ++total;
            }
            if(output != null)
                output.Close();
            return (double)correct / total;
        }
示例#8
0
 public static double PredictRaw(Model model, Node[] x)
 {
     var d = new double[1];
     Procedures.svm_predict_values(model, x, d);
     return d[0];
 }
示例#9
0
 /// <summary>
 /// Predict the class for a single input vector.
 /// </summary>
 /// <param name="model">The Model to use for prediction</param>
 /// <param name="x">The vector for which to predict class</param>
 /// <returns>The result</returns>
 public static double Predict(Model model, Node[] x)
 {
     return Procedures.svm_predict(model, x);
 }
示例#10
0
 /// <summary>
 /// Predicts a class distribution for the single input vector.
 /// </summary>
 /// <param name="model">Model to use for prediction</param>
 /// <param name="x">The vector for which to predict the class distribution</param>
 /// <returns>A probability distribtion over classes</returns>
 public static double[] PredictProbability(Model model, Node[] x)
 {
     SvmType svm_type = Procedures.svm_get_svm_type(model);
     if (svm_type != SvmType.C_SVC && svm_type != SvmType.NU_SVC)
         throw new Exception("Model type " + svm_type + " unable to predict probabilities.");
     int nr_class = Procedures.svm_get_nr_class(model);
     double[] probEstimates = new double[nr_class];
     Procedures.svm_predict_probability(model, x, probEstimates);
     return probEstimates;
 }
示例#11
0
        /// <summary>
        /// Writes a model to the provided stream.
        /// </summary>
        /// <param name="stream">The output stream</param>
        /// <param name="model">The model to write</param>
        public static void Write(Stream stream, Model model)
        {
            TemporaryCulture.Start();

            StreamWriter output = new StreamWriter(stream);

            Parameter param = model.Parameter;

            output.Write("svm_type " + param.SvmType + "\n");
            output.Write("kernel_type " + param.KernelType + "\n");

            if (param.KernelType == KernelType.POLY)
                output.Write("degree " + param.Degree + "\n");

            if (param.KernelType == KernelType.POLY || param.KernelType == KernelType.RBF || param.KernelType == KernelType.SIGMOID)
                output.Write("gamma " + param.Gamma + "\n");

            if (param.KernelType == KernelType.POLY || param.KernelType == KernelType.SIGMOID)
                output.Write("coef0 " + param.Coefficient0 + "\n");

            int nr_class = model.NumberOfClasses;
            int l = model.SupportVectorCount;
            output.Write("nr_class " + nr_class + "\n");
            output.Write("total_sv " + l + "\n");

            {
                output.Write("rho");
                for (int i = 0; i < nr_class * (nr_class - 1) / 2; i++)
                    output.Write(" " + model.Rho[i]);
                output.Write("\n");
            }

            if (model.ClassLabels != null)
            {
                output.Write("label");
                for (int i = 0; i < nr_class; i++)
                    output.Write(" " + model.ClassLabels[i]);
                output.Write("\n");
            }

            if (model.PairwiseProbabilityA != null)
            // regression has probA only
            {
                output.Write("probA");
                for (int i = 0; i < nr_class * (nr_class - 1) / 2; i++)
                    output.Write(" " + model.PairwiseProbabilityA[i]);
                output.Write("\n");
            }
            if (model.PairwiseProbabilityB != null)
            {
                output.Write("probB");
                for (int i = 0; i < nr_class * (nr_class - 1) / 2; i++)
                    output.Write(" " + model.PairwiseProbabilityB[i]);
                output.Write("\n");
            }

            if (model.NumberOfSVPerClass != null)
            {
                output.Write("nr_sv");
                for (int i = 0; i < nr_class; i++)
                    output.Write(" " + model.NumberOfSVPerClass[i]);
                output.Write("\n");
            }

            output.Write("SV\n");
            double[][] sv_coef = model.SupportVectorCoefficients;
            Node[][] SV = model.SupportVectors;

            for (int i = 0; i < l; i++)
            {
                for (int j = 0; j < nr_class - 1; j++)
                    output.Write(sv_coef[j][i] + " ");

                Node[] p = SV[i];
                if (p.Length == 0)
                {
                    output.WriteLine();
                    continue;
                }
                if (param.KernelType == KernelType.PRECOMPUTED)
                    output.Write("0:{0}", (int)p[0].Value);
                else
                {
                    output.Write("{0}:{1}", p[0].Index, p[0].Value);
                    for (int j = 1; j < p.Length; j++)
                        output.Write(" {0}:{1}", p[j].Index, p[j].Value);
                }
                output.WriteLine();
            }

            output.Flush();

            TemporaryCulture.Stop();
        }
示例#12
0
 /// <summary>
 /// Writes a model to the provided filename.  This will overwrite any previous data in the file.
 /// </summary>
 /// <param name="filename">The desired file</param>
 /// <param name="model">The Model to write</param>
 public static void Write(string filename, Model model)
 {
     FileStream stream = File.Open(filename, FileMode.Create);
     try
     {
         Write(stream, model);
     }
     finally
     {
         stream.Close();
     }
 }
示例#13
0
        /// <summary>
        /// Reads a Model from the provided stream.
        /// </summary>
        /// <param name="stream">The stream from which to read the Model.</param>
        /// <returns>the Model</returns>
        public static Model Read(Stream stream)
        {
            TemporaryCulture.Start();

            StreamReader input = new StreamReader(stream);

            // read parameters

            Model model = new Model();
            Parameter param = new Parameter();
            model.Parameter = param;
            model.Rho = null;
            model.PairwiseProbabilityA = null;
            model.PairwiseProbabilityB = null;
            model.ClassLabels = null;
            model.NumberOfSVPerClass = null;

            bool headerFinished = false;
            while (!headerFinished)
            {
                string line = input.ReadLine();
                string cmd, arg;
                int splitIndex = line.IndexOf(' ');
                if (splitIndex >= 0)
                {
                    cmd = line.Substring(0, splitIndex);
                    arg = line.Substring(splitIndex + 1);
                }
                else
                {
                    cmd = line;
                    arg = "";
                }
                arg = arg.ToLower();

                int i, n;
                switch (cmd)
                {
                    case "svm_type":
                        param.SvmType = (SvmType)Enum.Parse(typeof(SvmType), arg.ToUpper());
                        break;

                    case "kernel_type":
                        param.KernelType = (KernelType)Enum.Parse(typeof(KernelType), arg.ToUpper());
                        break;

                    case "degree":
                        param.Degree = int.Parse(arg);
                        break;

                    case "gamma":
                        param.Gamma = double.Parse(arg);
                        break;

                    case "coef0":
                        param.Coefficient0 = double.Parse(arg);
                        break;

                    case "nr_class":
                        model.NumberOfClasses = int.Parse(arg);
                        break;

                    case "total_sv":
                        model.SupportVectorCount = int.Parse(arg);
                        break;

                    case "rho":
                        n = model.NumberOfClasses * (model.NumberOfClasses - 1) / 2;
                        model.Rho = new double[n];
                        string[] rhoParts = arg.Split();
                        for (i = 0; i < n; i++)
                            model.Rho[i] = double.Parse(rhoParts[i]);
                        break;

                    case "label":
                        n = model.NumberOfClasses;
                        model.ClassLabels = new int[n];
                        string[] labelParts = arg.Split();
                        for (i = 0; i < n; i++)
                            model.ClassLabels[i] = int.Parse(labelParts[i]);
                        break;

                    case "probA":
                        n = model.NumberOfClasses * (model.NumberOfClasses - 1) / 2;
                        model.PairwiseProbabilityA = new double[n];
                        string[] probAParts = arg.Split();
                        for (i = 0; i < n; i++)
                            model.PairwiseProbabilityA[i] = double.Parse(probAParts[i]);
                        break;

                    case "probB":
                        n = model.NumberOfClasses * (model.NumberOfClasses - 1) / 2;
                        model.PairwiseProbabilityB = new double[n];
                        string[] probBParts = arg.Split();
                        for (i = 0; i < n; i++)
                            model.PairwiseProbabilityB[i] = double.Parse(probBParts[i]);
                        break;

                    case "nr_sv":
                        n = model.NumberOfClasses;
                        model.NumberOfSVPerClass = new int[n];
                        string[] nrsvParts = arg.Split();
                        for (i = 0; i < n; i++)
                            model.NumberOfSVPerClass[i] = int.Parse(nrsvParts[i]);
                        break;

                    case "SV":
                        headerFinished = true;
                        break;

                    default:
                        throw new Exception("Unknown text in model file");
                }
            }

            // read sv_coef and SV

            int m = model.NumberOfClasses - 1;
            int l = model.SupportVectorCount;
            model.SupportVectorCoefficients = new double[m][];
            for (int i = 0; i < m; i++)
            {
                model.SupportVectorCoefficients[i] = new double[l];
            }
            model.SupportVectors = new Node[l][];

            for (int i = 0; i < l; i++)
            {
                string[] parts = input.ReadLine().Trim().Split();

                for (int k = 0; k < m; k++)
                    model.SupportVectorCoefficients[k][i] = double.Parse(parts[k]);
                int n = parts.Length - m;
                model.SupportVectors[i] = new Node[n];
                for (int j = 0; j < n; j++)
                {
                    string[] nodeParts = parts[m + j].Split(':');
                    model.SupportVectors[i][j] = new Node();
                    model.SupportVectors[i][j].Index = int.Parse(nodeParts[0]);
                    model.SupportVectors[i][j].Value = double.Parse(nodeParts[1]);
                }
            }

            TemporaryCulture.Stop();

            return model;
        }
示例#14
0
文件: Solver.cs 项目: wendelad/RecSys
        public static void svm_predict_values(Model model, Node[] x, double[] dec_values)
        {
            if (model.Parameter.SvmType == SvmType.ONE_CLASS ||
               model.Parameter.SvmType == SvmType.EPSILON_SVR ||
               model.Parameter.SvmType == SvmType.NU_SVR)
            {
                double[] sv_coef = model.SupportVectorCoefficients[0];
                double sum = 0;
                for (int i = 0; i < model.SupportVectorCount; i++)
                    sum += sv_coef[i] * Kernel.KernelFunction(x, model.SupportVectors[i], model.Parameter);
                sum -= model.Rho[0];
                dec_values[0] = sum;
            }
            else
            {
                int i;
                int nr_class = model.NumberOfClasses;
                int l = model.SupportVectorCount;

                double[] kvalue = new double[l];
                for (i = 0; i < l; i++)
                    kvalue[i] = Kernel.KernelFunction(x, model.SupportVectors[i], model.Parameter);

                int[] start = new int[nr_class];
                start[0] = 0;
                for (i = 1; i < nr_class; i++)
                    start[i] = start[i - 1] + model.NumberOfSVPerClass[i - 1];

                int p = 0;
                for (i = 0; i < nr_class; i++)
                    for (int j = i + 1; j < nr_class; j++)
                    {
                        double sum = 0;
                        int si = start[i];
                        int sj = start[j];
                        int ci = model.NumberOfSVPerClass[i];
                        int cj = model.NumberOfSVPerClass[j];

                        int k;
                        double[] coef1 = model.SupportVectorCoefficients[j - 1];
                        double[] coef2 = model.SupportVectorCoefficients[i];
                        for (k = 0; k < ci; k++)
                            sum += coef1[si + k] * kvalue[si + k];
                        for (k = 0; k < cj; k++)
                            sum += coef2[sj + k] * kvalue[sj + k];
                        sum -= model.Rho[p];
                        dec_values[p] = sum;
                        p++;
                    }
            }
        }
示例#15
0
文件: Solver.cs 项目: wendelad/RecSys
 public static int svm_check_probability_model(Model model)
 {
     if (((model.Parameter.SvmType == SvmType.C_SVC || model.Parameter.SvmType == SvmType.NU_SVC) &&
     model.PairwiseProbabilityA != null && model.PairwiseProbabilityB != null) ||
     ((model.Parameter.SvmType == SvmType.EPSILON_SVR || model.Parameter.SvmType == SvmType.NU_SVR) &&
      model.PairwiseProbabilityA != null))
         return 1;
     else
         return 0;
 }
示例#16
0
文件: Solver.cs 项目: wendelad/RecSys
        //
        // Interface functions
        //
        public static Model svm_train(Problem prob, Parameter param)
        {
            Model model = new Model();
            model.Parameter = param;

            if (param.SvmType == SvmType.ONE_CLASS ||
               param.SvmType == SvmType.EPSILON_SVR ||
               param.SvmType == SvmType.NU_SVR)
            {
                // regression or one-class-svm
                model.NumberOfClasses = 2;
                model.ClassLabels = null;
                model.NumberOfSVPerClass = null;
                model.PairwiseProbabilityA = null; model.PairwiseProbabilityB = null;
                model.SupportVectorCoefficients = new double[1][];

                if (param.Probability &&
                   (param.SvmType == SvmType.EPSILON_SVR ||
                    param.SvmType == SvmType.NU_SVR))
                {
                    model.PairwiseProbabilityA = new double[1];
                    model.PairwiseProbabilityA[0] = svm_svr_probability(prob, param);
                }

                decision_function f = svm_train_one(prob, param, 0, 0);
                model.Rho = new double[1];
                model.Rho[0] = f.rho;

                int nSV = 0;
                int i;
                for (i = 0; i < prob.Count; i++)
                    if (Math.Abs(f.alpha[i]) > 0) ++nSV;
                model.SupportVectorCount = nSV;
                model.SupportVectors = new Node[nSV][];
                model.SupportVectorCoefficients[0] = new double[nSV];
                int j = 0;
                for (i = 0; i < prob.Count; i++)
                    if (Math.Abs(f.alpha[i]) > 0)
                    {
                        model.SupportVectors[j] = prob.X[i];
                        model.SupportVectorCoefficients[0][j] = f.alpha[i];
                        ++j;
                    }
            }
            else
            {
                // classification
                int l = prob.Count;
                int[] tmp_nr_class = new int[1];
                int[][] tmp_label = new int[1][];
                int[][] tmp_start = new int[1][];
                int[][] tmp_count = new int[1][];
                int[] perm = new int[l];

                // group training data of the same class
                svm_group_classes(prob, tmp_nr_class, tmp_label, tmp_start, tmp_count, perm);
                int nr_class = tmp_nr_class[0];
                int[] label = tmp_label[0];
                int[] start = tmp_start[0];
                int[] count = tmp_count[0];
                Node[][] x = new Node[l][];
                int i;
                for (i = 0; i < l; i++)
                    x[i] = prob.X[perm[i]];

                // calculate weighted C

                double[] weighted_C = new double[nr_class];
                for (i = 0; i < nr_class; i++)
                    weighted_C[i] = param.C;
                foreach (int weightedLabel in param.Weights.Keys)
                {
                    int index = Array.IndexOf<int>(label, weightedLabel);
                    if (index < 0)
                        Console.Error.WriteLine("warning: class label " + weightedLabel + " specified in weight is not found");
                    else weighted_C[index] *= param.Weights[weightedLabel];
                }

                // train k*(k-1)/2 models

                bool[] nonzero = new bool[l];
                for (i = 0; i < l; i++)
                    nonzero[i] = false;
                decision_function[] f = new decision_function[nr_class * (nr_class - 1) / 2];

                double[] probA = null, probB = null;
                if (param.Probability)
                {
                    probA = new double[nr_class * (nr_class - 1) / 2];
                    probB = new double[nr_class * (nr_class - 1) / 2];
                }

                int p = 0;
                for (i = 0; i < nr_class; i++)
                    for (int j = i + 1; j < nr_class; j++)
                    {
                        Problem sub_prob = new Problem();
                        int si = start[i], sj = start[j];
                        int ci = count[i], cj = count[j];
                        sub_prob.Count = ci + cj;
                        sub_prob.X = new Node[sub_prob.Count][];
                        sub_prob.Y = new double[sub_prob.Count];
                        int k;
                        for (k = 0; k < ci; k++)
                        {
                            sub_prob.X[k] = x[si + k];
                            sub_prob.Y[k] = +1;
                        }
                        for (k = 0; k < cj; k++)
                        {
                            sub_prob.X[ci + k] = x[sj + k];
                            sub_prob.Y[ci + k] = -1;
                        }

                        if (param.Probability)
                        {
                            double[] probAB = new double[2];
                            svm_binary_svc_probability(sub_prob, param, weighted_C[i], weighted_C[j], probAB);
                            probA[p] = probAB[0];
                            probB[p] = probAB[1];
                        }

                        f[p] = svm_train_one(sub_prob, param, weighted_C[i], weighted_C[j]);
                        for (k = 0; k < ci; k++)
                            if (!nonzero[si + k] && Math.Abs(f[p].alpha[k]) > 0)
                                nonzero[si + k] = true;
                        for (k = 0; k < cj; k++)
                            if (!nonzero[sj + k] && Math.Abs(f[p].alpha[ci + k]) > 0)
                                nonzero[sj + k] = true;
                        ++p;
                    }

                // build output

                model.NumberOfClasses = nr_class;

                model.ClassLabels = new int[nr_class];
                for (i = 0; i < nr_class; i++)
                    model.ClassLabels[i] = label[i];

                model.Rho = new double[nr_class * (nr_class - 1) / 2];
                for (i = 0; i < nr_class * (nr_class - 1) / 2; i++)
                    model.Rho[i] = f[i].rho;

                if (param.Probability)
                {
                    model.PairwiseProbabilityA = new double[nr_class * (nr_class - 1) / 2];
                    model.PairwiseProbabilityB = new double[nr_class * (nr_class - 1) / 2];
                    for (i = 0; i < nr_class * (nr_class - 1) / 2; i++)
                    {
                        model.PairwiseProbabilityA[i] = probA[i];
                        model.PairwiseProbabilityB[i] = probB[i];
                    }
                }
                else
                {
                    model.PairwiseProbabilityA = null;
                    model.PairwiseProbabilityB = null;
                }

                int nnz = 0;
                int[] nz_count = new int[nr_class];
                model.NumberOfSVPerClass = new int[nr_class];
                for (i = 0; i < nr_class; i++)
                {
                    int nSV = 0;
                    for (int j = 0; j < count[i]; j++)
                        if (nonzero[start[i] + j])
                        {
                            ++nSV;
                            ++nnz;
                        }
                    model.NumberOfSVPerClass[i] = nSV;
                    nz_count[i] = nSV;
                }

                Procedures.info("Total nSV = " + nnz + "\n");

                model.SupportVectorCount = nnz;
                model.SupportVectors = new Node[nnz][];
                p = 0;
                for (i = 0; i < l; i++)
                    if (nonzero[i]) model.SupportVectors[p++] = x[i];

                int[] nz_start = new int[nr_class];
                nz_start[0] = 0;
                for (i = 1; i < nr_class; i++)
                    nz_start[i] = nz_start[i - 1] + nz_count[i - 1];

                model.SupportVectorCoefficients = new double[nr_class - 1][];
                for (i = 0; i < nr_class - 1; i++)
                    model.SupportVectorCoefficients[i] = new double[nnz];

                p = 0;
                for (i = 0; i < nr_class; i++)
                    for (int j = i + 1; j < nr_class; j++)
                    {
                        // classifier (i,j): coefficients with
                        // i are in sv_coef[j-1][nz_start[i]...],
                        // j are in sv_coef[i][nz_start[j]...]

                        int si = start[i];
                        int sj = start[j];
                        int ci = count[i];
                        int cj = count[j];

                        int q = nz_start[i];
                        int k;
                        for (k = 0; k < ci; k++)
                            if (nonzero[si + k])
                                model.SupportVectorCoefficients[j - 1][q++] = f[p].alpha[k];
                        q = nz_start[j];
                        for (k = 0; k < cj; k++)
                            if (nonzero[sj + k])
                                model.SupportVectorCoefficients[i][q++] = f[p].alpha[ci + k];
                        ++p;
                    }
            }
            return model;
        }
示例#17
0
        public override ClassifierResult Build()
        {
            //For this example (and indeed, many scenarios), the default
            //parameters will suffice.
            Parameter parameters = new Parameter();
            double C;
            double Gamma;

            //This will do a grid optimization to find the best parameters
            //and store them in C and Gamma, outputting the entire
            //search to params.txt.

            ParameterSelection.Grid(_trainProblem, parameters, "params.txt", out C, out Gamma);
            parameters.C = C;
            parameters.Gamma = Gamma;

            //Train the model using the optimal parameters.

            _model = Training.Train(_trainProblem, parameters);

            // пробегаем по всем клиентски данным и сохраняем результат
            var probDictList = new Dictionary<string, Dictionary<int, double>>();
            foreach (string id in _testDataDict.Keys)
            {
                if (!probDictList.ContainsKey(id))
                    probDictList.Add(id, new Dictionary<int, double>());

                foreach (var sarr in _testDataDict[id])
                {
                    var y = PredictProba(sarr);

                    double prob = y.Probs[1];
                    int kmax = probDictList[id].Keys.Count == 0 ? 0 : probDictList[id].Keys.Max() + 1;
                    probDictList[id].Add(kmax, prob);
                }
            }

            // вероятность дефолта определяется как среднее по записям для клиента
            var probDict = new Dictionary<string, double>();
            foreach (var id in probDictList.Keys)
            {
                int cnt = probDictList[id].Keys.Count();
                double prob = 0;
                foreach (var d in probDictList[id].Keys)
                {
                    prob += probDictList[id][d];
                }

                if (!probDict.ContainsKey(id))
                    probDict.Add(id, prob / cnt);
            }

            // находим статистики классификации
            var rlist = new RocItem[_resultDict.Count]; // массив для оценки результата
            int idx = 0;
            foreach (string id in probDict.Keys)
            {
                if (rlist[idx] == null) rlist[idx] = new RocItem();

                rlist[idx].Prob = probDict[id]; // среднее по наблюдениям
                rlist[idx].Target = _resultDict[id];
                rlist[idx].Predicted = 0;

                idx++;
            }
            Array.Sort(rlist, (o1, o2) => (1 - o1.Prob).CompareTo(1 - o2.Prob));
            var cres = ResultCalc.GetResult(rlist, 0.05);

            var clsRes = new ClassifierResult();
            clsRes.BestResult = cres;
            clsRes.LastResult = cres;
            clsRes.ResDict.Add(0, cres);

            return clsRes;
        }