public void RunTest()
{
double[][] input =
{
new double[] { 55, 0 }, // 0 - no cancer
new double[] { 28, 0 }, // 0
new double[] { 65, 1 }, // 0
new double[] { 46, 0 }, // 1 - have cancer
new double[] { 86, 1 }, // 1
new double[] { 56, 1 }, // 1
new double[] { 85, 0 }, // 0
new double[] { 33, 0 }, // 0
new double[] { 21, 1 }, // 0
new double[] { 42, 1 }, // 1
};
double[] output =
{
0, 0, 0, 1, 1, 1, 0, 0, 0, 1
};
int[] labels = output.Apply(x => x > 0 ? +1 : -1);
var svm = new SupportVectorMachine(inputs: 2);
var teacher = new ProbabilisticCoordinateDescent(svm, input, labels);
teacher.Tolerance = 1e-10;
teacher.Complexity = 1e+10;
Assert.IsFalse(svm.IsProbabilistic);
double error = teacher.Run();
Assert.IsTrue(svm.IsProbabilistic);
var regression = LogisticRegression.FromWeights(svm.ToWeights());
double[] actual = new double[output.Length];
for (int i = 0; i < actual.Length; i++)
actual[i] = regression.Compute(input[i]);
double ageOdds = regression.GetOddsRatio(1); // 1.0208597028836701
double smokeOdds = regression.GetOddsRatio(2); // 5.8584748789881331
Assert.AreEqual(0.2, error);
Assert.AreEqual(1.0208597028836701, ageOdds, 1e-4);
Assert.AreEqual(5.8584748789881331, smokeOdds, 1e-4);
Assert.IsFalse(Double.IsNaN(ageOdds));
Assert.IsFalse(Double.IsNaN(smokeOdds));
Assert.AreEqual(-2.4577464307294092, regression.Intercept, 1e-8);
Assert.AreEqual(-2.4577464307294092, regression.Coefficients[0], 1e-8);
Assert.AreEqual(0.020645118265359252, regression.Coefficients[1], 1e-8);
Assert.AreEqual(1.7678893101571855, regression.Coefficients[2], 1e-8);
}
public void KernelTest1()
{
var dataset = SequentialMinimalOptimizationTest.yinyang;
double[][] inputs = dataset.Submatrix(null, 0, 1).ToArray();
int[] labels = dataset.GetColumn(2).ToInt32();
double e1, e2;
double[] w1, w2;
{
Accord.Math.Tools.SetupGenerator(0);
var svm = new SupportVectorMachine(inputs: 2);
var teacher = new ProbabilisticCoordinateDescent(svm, inputs, labels);
teacher.Tolerance = 1e-10;
teacher.Complexity = 1e+10;
e1 = teacher.Run();
w1 = svm.ToWeights();
}
{
Accord.Math.Tools.SetupGenerator(0);
var svm = new KernelSupportVectorMachine(new Linear(0), inputs: 2);
var teacher = new ProbabilisticCoordinateDescent(svm, inputs, labels);
teacher.Tolerance = 1e-10;
teacher.Complexity = 1e+10;
e2 = teacher.Run();
w2 = svm.ToWeights();
}
Assert.AreEqual(e1, e2);
Assert.AreEqual(w1.Length, w2.Length);
Assert.AreEqual(w1[0], w2[0]);
Assert.AreEqual(w1[1], w2[1]);
Assert.AreEqual(w1[2], w2[2]);
}
public void RunTest2()
{
var dataset = SequentialMinimalOptimizationTest.yinyang;
double[][] inputs = dataset.Submatrix(null, 0, 1).ToArray();
int[] labels = dataset.GetColumn(2).ToInt32();
var svm = new SupportVectorMachine(inputs: 2);
var teacher = new ProbabilisticCoordinateDescent(svm, inputs, labels);
teacher.Tolerance = 1e-10;
teacher.Complexity = 1e+10;
double error = teacher.Run();
double[] weights = svm.ToWeights();
Assert.AreEqual(0.12, error);
Assert.AreEqual(3, weights.Length);
Assert.AreEqual(-1.3231203367770932, weights[0]);
Assert.AreEqual(-3.0227742288788493, weights[1]);
Assert.AreEqual(-0.73074823290553259, weights[2]);
Assert.AreEqual(svm.Threshold, weights[0]);
}
public void KernelTest2()
{
var dataset = SequentialMinimalOptimizationTest.yinyang;
var inputs = dataset.Submatrix(null, 0, 1).ToJagged();
var labels = dataset.GetColumn(2).ToInt32();
var svm = new KernelSupportVectorMachine(new Linear(1), inputs: 2);
var p = new ProbabilisticCoordinateDescent(svm, inputs, labels);
Assert.NotNull(p);
}
public static void train_one(Problem prob, Parameters param, out double[] w, double Cp, double Cn)
{
double[][] inputs = prob.Inputs;
int[] labels = prob.Outputs.Apply(x => x >= 0 ? 1 : -1);
double eps = param.Tolerance;
int pos = 0;
for (int i = 0; i < labels.Length; i++)
if (labels[i] >= 0) pos++;
int neg = prob.Outputs.Length - pos;
double primal_solver_tol = eps * Math.Max(Math.Min(pos, neg), 1.0) / prob.Inputs.Length;
SupportVectorMachine svm = new SupportVectorMachine(prob.Dimensions);
ISupportVectorMachineLearning teacher = null;
switch (param.Solver)
{
case LibSvmSolverType.L2RegularizedLogisticRegression:
// l2r_lr_fun
teacher = new ProbabilisticNewtonMethod(svm, inputs, labels)
{
PositiveWeight = Cp,
NegativeWeight = Cn,
Tolerance = primal_solver_tol
}; break;
case LibSvmSolverType.L2RegularizedL2LossSvc:
// fun_obj=new l2r_l2_svc_fun(prob, C);
teacher = new LinearNewtonMethod(svm, inputs, labels)
{
PositiveWeight = Cp,
NegativeWeight = Cn,
Tolerance = primal_solver_tol
}; break;
case LibSvmSolverType.L2RegularizedL2LossSvcDual:
// solve_l2r_l1l2_svc(prob, w, eps, Cp, Cn, L2R_L2LOSS_SVC_DUAL);
teacher = new LinearCoordinateDescent(svm, inputs, labels)
{
Loss = Loss.L2,
PositiveWeight = Cp,
NegativeWeight = Cn,
}; break;
case LibSvmSolverType.L2RegularizedL1LossSvcDual:
// solve_l2r_l1l2_svc(prob, w, eps, Cp, Cn, L2R_L1LOSS_SVC_DUAL);
teacher = new LinearCoordinateDescent(svm, inputs, labels)
{
Loss = Loss.L1,
PositiveWeight = Cp,
NegativeWeight = Cn,
}; break;
case LibSvmSolverType.L1RegularizedLogisticRegression:
// solve_l1r_lr(&prob_col, w, primal_solver_tol, Cp, Cn);
teacher = new ProbabilisticCoordinateDescent(svm, inputs, labels)
{
PositiveWeight = Cp,
NegativeWeight = Cn,
Tolerance = primal_solver_tol
}; break;
case LibSvmSolverType.L2RegularizedLogisticRegressionDual:
// solve_l2r_lr_dual(prob, w, eps, Cp, Cn);
teacher = new ProbabilisticDualCoordinateDescent(svm, inputs, labels)
{
PositiveWeight = Cp,
NegativeWeight = Cn,
Tolerance = primal_solver_tol,
}; break;
}
Trace.WriteLine("Training " + param.Solver);
// run the learning algorithm
var sw = Stopwatch.StartNew();
double error = teacher.Run();
sw.Stop();
// save the solution
w = svm.ToWeights();
Trace.WriteLine(String.Format("Finished {0}: {1} in {2}",
param.Solver, error, sw.Elapsed));
}
/// <summary>
/// Creates a Support Vector Machine and teaches it to recognize
/// the previously loaded dataset using the current UI settings.
/// </summary>
///
private void btnCreate_Click(object sender, EventArgs e)
{
if (dgvLearningSource.DataSource == null)
{
MessageBox.Show("Please load some data first.");
return;
}
// Finishes and save any pending changes to the given data
dgvLearningSource.EndEdit();
// Creates a matrix from the entire source data table
double[,] table = (dgvLearningSource.DataSource as DataTable).ToMatrix(out columnNames);
// Get only the input vector values (first two columns)
double[][] inputs = table.GetColumns(0, 1).ToArray();
// Get only the output labels (last column)
int[] outputs = table.GetColumn(2).ToInt32();
// Create a sparse logistic learning algorithm
var pcd = new ProbabilisticCoordinateDescent()
{
// Set learning parameters
Complexity = (double)numC.Value,
Tolerance = (double)numT.Value,
PositiveWeight = (double)numPositiveWeight.Value,
NegativeWeight = (double)numNegativeWeight.Value,
};
try
{
// Run
svm = pcd.Learn(inputs, outputs);
lbStatus.Text = "Training complete!";
}
catch (ConvergenceException)
{
lbStatus.Text = "Convergence could not be attained. " +
"The learned machine might still be usable.";
}
svm.Compress(); // reduce support vectors to a single weight vector
Trace.Assert(svm.SupportVectors.Length == 1);
Trace.Assert(svm.Weights.Length == 1);
createSurface(table);
// Show feature weight importance
double[] weights = svm.SupportVectors[0].Abs();
string[] featureNames = columnNames.RemoveAt(columnNames.Length - 1);
dgvSupportVectors.DataSource = new ArrayDataView(weights, featureNames);
CreateBarGraph(weights, featureNames);
}
