@Override
public AnalysisCollector analyze(CollectionReader cr) throws AnalyzerFailureException {
svm_problem svmProblem = loadData(cr);
svm_problem sampled = null;
if (findBestParameters) {
if (sample < 1d) {
logger.debug("Sampling.");
sampled = do_sample(svmProblem);
}
logger.debug("Performing grid search.");
do_find_best_parameters(sampled != null ? sampled : svmProblem);
}
svm_parameter svmParam = getDefaultSvmParameters();
svmParam.probability = 1;
svmParam.C = c;
svmParam.gamma = gamma;
setWeights(svmParam);
logger.debug("Training with C=" + c + " gamma=" + gamma);
svm_model model = svm.svm_train(svmProblem, svmParam);
logger.debug("Done!");
return new SingletonAnalysisCollector(
new LibSvmTrainerAnalysis(model, scaler, labelList, c, gamma));
}
public static void svmTrain(ArrayList<ArrayList<Double>> train) {
svm_problem prob = new svm_problem();
int dataCount = train.size();
prob.y = new double[dataCount];
prob.l = dataCount;
prob.x = new svm_node[dataCount][];
for (int i = 0; i < dataCount; i++) {
ArrayList<Double> features = train.get(i);
prob.x[i] = new svm_node[features.size() - 1];
for (int j = 1; j < features.size(); j++) {
svm_node node = new svm_node();
node.index = j - 1;
node.value = features.get(j);
prob.x[i][j - 1] = node;
}
prob.y[i] = features.get(0);
}
svm_parameter param = new svm_parameter();
param.probability = 1;
param.gamma = 0.5;
param.nu = 0.5;
param.C = 1;
param.svm_type = svm_parameter.NU_SVC;
param.kernel_type = svm_parameter.LINEAR;
param.cache_size = 20000;
param.eps = 0.001;
_model = svm.svm_train(prob, param);
}
private void setWeights(svm_parameter svmParam) {
if (weights != null) {
svmParam.nr_weight = weights.size();
svmParam.weight_label = new int[weights.size()];
svmParam.weight = new double[weights.size()];
for (int i = 0; i < weights.size(); ++i) {
svmParam.weight_label[i] = i;
svmParam.weight[i] = weights.get(i);
}
logger.debug("Class weights: " + weights);
}
}
public static void trainClassifier(
List<TrainingSample<BxZoneLabel>> trainingElements, String output)
throws AnalysisException, IOException {
SVMHeaderLinesClassifier contentFilter = new SVMHeaderLinesClassifier();
svm_parameter param = SVMZoneClassifier.getDefaultParam();
param.gamma = BEST_GAMMA;
param.C = BEST_C;
param.kernel_type = svm_parameter.RBF;
contentFilter.setParameter(param);
contentFilter.buildClassifier(trainingElements);
contentFilter.saveModel(output);
}
private void read_problem() throws IOException {
BufferedReader fp = new BufferedReader(new FileReader(input_file_name));
Vector<Double> vy = new Vector<Double>();
Vector<svm_node[]> vx = new Vector<svm_node[]>();
int max_index = 0;
while (true) {
String line = fp.readLine();
if (line == null) break;
StringTokenizer st = new StringTokenizer(line, " \t\n\r\f:");
vy.addElement(atof(st.nextToken()));
int m = st.countTokens() / 2;
svm_node[] x = new svm_node[m];
for (int j = 0; j < m; j++) {
x[j] = new svm_node();
x[j].index = atoi(st.nextToken());
x[j].value = atof(st.nextToken());
}
if (m > 0) max_index = Math.max(max_index, x[m - 1].index);
vx.addElement(x);
}
prob = new svm_problem();
prob.l = vy.size();
prob.x = new svm_node[prob.l][];
for (int i = 0; i < prob.l; i++) prob.x[i] = vx.elementAt(i);
prob.y = new double[prob.l];
for (int i = 0; i < prob.l; i++) prob.y[i] = vy.elementAt(i);
if (param.gamma == 0 && max_index > 0) param.gamma = 1.0 / max_index;
fp.close();
}
public static void train(svm_problem svmProblem) {
defaultSVMParameter = new DefaultSVMParameter(LoadFeatureFile.f);
svmParameter = defaultSVMParameter.svmParameter;
filename += ".model";
// Change the parameters with the desired C and Gamma
svmParameter.C = 0.125;
svmParameter.gamma = 0.5;
// Train the SVM
svmModel = svm.svm_train(svmProblem, svmParameter);
try {
svm.svm_save_model(filename, svmModel);
} catch (IOException e) {
e.printStackTrace();
}
}
public SVM train(InstanceList trainingList) {
svm_problem problem = new svm_problem();
problem.l = trainingList.size();
problem.x = new svm_node[problem.l][];
problem.y = new double[problem.l];
for (int i = 0; i < trainingList.size(); i++) {
Instance instance = trainingList.get(i);
svm_node[] input = SVM.getSvmNodes(instance);
if (input == null) {
continue;
}
int labelIndex = ((Label) instance.getTarget()).getIndex();
problem.x[i] = input;
problem.y[i] = labelIndex;
}
int max_index = trainingList.getDataAlphabet().size();
if (param.gamma == 0 && max_index > 0) {
param.gamma = 1.0 / max_index;
}
// int numLabels = trainingList.getTargetAlphabet().size();
// int[] weight_label = new int[numLabels];
// double[] weight = trainingList.targetLabelDistribution().getValues();
// double minValue = Double.MAX_VALUE;
//
// for (int i = 0; i < weight.length; i++) {
// if (minValue > weight[i]) {
// minValue = weight[i];
// }
// }
//
// for (int i = 0; i < weight.length; i++) {
// weight_label[i] = i;
// weight[i] = weight[i] / minValue;
// }
//
// param.weight_label = weight_label;
// param.weight = weight;
String error_msg = svm.svm_check_parameter(problem, param);
if (error_msg != null) {
System.err.print("Error: " + error_msg + "\n");
System.exit(1);
}
svm_model model = svm.svm_train(problem, param);
classifier = new SVM(model, trainingList.getPipe());
return classifier;
}
public svm_parameter setupSVM() {
svm_parameter param = new svm_parameter();
param.probability = 0;
param.gamma = 0.5;
// param.nu = 0.5;
param.C = 0.5;
param.svm_type = svm_parameter.EPSILON_SVR;
param.kernel_type = svm_parameter.POLY;
param.cache_size = 20000;
param.eps = 0.001;
return param;
}
public SVMTrainer() {
svm_parameter param = new svm_parameter();
param.svm_type = svm_parameter.C_SVC;
param.kernel_type = svm_parameter.RBF;
param.degree = 3;
param.gamma = 0; // 1/num_features
param.coef0 = 0;
param.nu = 0.5;
param.cache_size = 100;
param.C = 1;
param.eps = 1e-3;
param.p = 0.1;
param.shrinking = 0;
param.probability = 1;
param.nr_weight = 0;
param.weight_label = new int[0];
param.weight = new double[0];
setParameter(param);
}
@Override
public void train(List<Input> inputs) throws Exception {
// What is the balance of the data set?
Map<Integer, Integer> labelCounts = new HashMap<Integer, Integer>();
for (Input input : inputs) {
int thisLabel = (input.label == label ? 1 : -1);
if (!labelCounts.containsKey(thisLabel)) {
labelCounts.put(thisLabel, 1);
} else {
labelCounts.put(thisLabel, labelCounts.get(thisLabel) + 1);
}
}
// How many models do we need to train?
int modelCount =
(int) Math.ceil(labelCounts.get(-1).intValue() / labelCounts.get(1).intValue());
for (int i = 0; i < modelCount; i++) {
svm_problem problem = new svm_problem();
// l appears to be the number of training samples
problem.l = labelCounts.get(1) * 2;
// The features of each sample
svm_node[][] svmTrainingSamples = new svm_node[problem.l][];
double[] labels = new double[problem.l];
int count = 0;
// Get all of the 1-labeled inputs
for (Input input : inputs) {
if (input.label == label) {
svmTrainingSamples[count] = input.getSVMFeatures();
labels[count++] = 1;
}
}
// Randomly get -1-labeled inputs
for (int j = 0; j < labelCounts.get(1); j++) {
Input input = inputs.get(MathUtils.RANDOM.nextInt(inputs.size()));
if (input.label == label) {
j--;
continue;
}
svmTrainingSamples[count] = input.getSVMFeatures();
labels[count++] = -1;
}
problem.x = svmTrainingSamples;
// y is probably the labels to each sample
problem.y = labels;
// Set the training parameters
svm_parameter param = new svm_parameter();
// SVM Type
// 0 -- C-SVC (classification)
// 1 -- nu-SVC (classification)
// 2 -- one-class SVM
// 3 -- epsilon-SVR (regression)
// 4 -- nu-SVR (regression)
param.svm_type = svm_parameter.C_SVC;
// Other C-SVC parameters:
// param.weight[] : sets the parameter C of class i to weight*c (default 1)
// param.C : cost, set the parameter C of C-SVC (default 1)
// Type of kernel
// 0 -- linear: u'*v
// 1 -- polynomial: (gamma*u'*v + coef0)^degree
// 2 -- radial basis function: exp(-gamma*|u-v|^2)
// 3 -- sigmoid: tanh(gamma*u'*v + coef0)
param.kernel_type = svm_parameter.RBF;
// Kernel gamma
param.gamma = 2e9;
// Cost
param.C = 2e9;
// Degree for poly
param.degree = 3;
// Coefficient for poly/sigmoid
param.coef0 = 0.1;
// Stopping criteria
param.eps = 0.05;
// Make larger for faster training
param.cache_size = 800;
// Number of label weights
param.nr_weight = 2;
// Weight labels
param.weight_label = new int[] {1, -1};
param.weight = new double[] {1, 1};
// Nu
param.nu = 0.1;
// p
param.p = 0.1;
// Shrinking heuristic
param.shrinking = 1;
// Estimate probabilities
param.probability = 0;
// Train the SVM classifier
svm.svm_set_print_string_function(
new svm_print_interface() {
@Override
public void print(String s) {}
});
svm_model model = svm.svm_train(problem, param);
models.add(model);
}
}
public svm_parameter getDefaultSvmParameters() {
svm_parameter param = new svm_parameter();
// default values
param.svm_type = svm_parameter.C_SVC;
param.kernel_type = svm_parameter.RBF;
param.degree = 3;
param.gamma = 0; // 1/num_features
param.coef0 = 0;
param.nu = 0.5;
param.cache_size = 100;
param.C = 1;
param.eps = 1e-3;
param.p = 0.1;
param.shrinking = 1;
param.probability = 0;
param.nr_weight = 0;
param.weight_label = new int[0];
param.weight = new double[0];
return param;
}
private void do_find_best_parameters(svm_problem svmProblem) {
svm_parameter svmParam = getDefaultSvmParameters();
setWeights(svmParam);
int maxIter =
((int) Math.ceil(Math.abs((log2cEnd - log2cBegin) / log2cStep)) + 1)
* ((int) Math.ceil(Math.abs((log2gEnd - log2gBegin) / log2gStep)) + 1);
// Run the grid search in separate CV threads
ExecutorService executorService = Executors.newFixedThreadPool(numberOfThreads);
List<CvParams> cvParamsList = new ArrayList<CvParams>();
for (double log2c = log2cBegin;
(log2cBegin < log2cEnd && log2c <= log2cEnd)
|| (log2cBegin >= log2cEnd && log2c >= log2cEnd);
log2c += log2cStep) {
double c1 = Math.pow(2, log2c);
for (double log2g = log2gBegin;
(log2gBegin < log2gEnd && log2g <= log2gEnd)
|| (log2gBegin >= log2gEnd && log2g >= log2gEnd);
log2g += log2gStep) {
double gamma1 = Math.pow(2, log2g);
svm_parameter svmParam1 = (svm_parameter) svmParam.clone();
svmParam1.C = c1;
svmParam1.gamma = gamma1;
executorService.execute(
new RunnableSvmCrossValidator(svmProblem, svmParam1, nrFold, cvParamsList));
}
}
// now wait for all threads to complete by calling shutdown
// note that this will NOT terminate the currently running threads, it just signals the thread
// pool to closeWriter
// once all work is completed
executorService.shutdown();
while (!executorService.isTerminated()) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// don't care if we get interrupted
}
// every second, report statistics
logger.debug(
String.format("%% complete: %5.2f", cvParamsList.size() / (double) maxIter * 100));
CvParams best = getBestCvParams(cvParamsList);
CvParams worst = getWorstcvParams(cvParamsList);
if (best != null) {
logger.debug("Best accuracy: " + best.accuracy);
logger.debug("Best C: " + best.c);
logger.debug("Best Gamma: " + best.gamma);
}
if (worst != null) {
logger.debug("Worst accuracy: " + worst.accuracy);
}
}
CvParams best = getBestCvParams(cvParamsList);
CvParams worst = getWorstcvParams(cvParamsList);
if (best != null) {
logger.debug("Best accuracy: " + best.accuracy);
logger.debug("Best C: " + best.c);
logger.debug("Best Gamma: " + best.gamma);
c = best.c;
gamma = best.gamma;
} else {
logger.error("Best CV parameters is null.");
}
if (worst != null) {
logger.debug("Worst accuracy: " + worst.accuracy);
}
}
