public void Logistic_Regression_Test_CostFunction_1()
{
Matrix X = new[, ]
{
{ 1, 1, 1 },
{ 1, 1, 1 },
{ 1, 1, 1 },
{ 8, 1, 6 },
{ 3, 5, 7 },
{ 4, 9, 2 }
};
Vector y = new Vector(new double[] { 1, 0, 1, 0, 1, 0 });
Vector theta = new Vector(new double[] { 0, 1, 0 });
ICostFunction logisticCostFunction = new LogisticCostFunction()
{
X = X,
Y = y,
Lambda = 3,
Regularizer = new L2Regularizer()
};
double cost = logisticCostFunction.ComputeCost(theta.Copy());
theta = logisticCostFunction.ComputeGradient(theta.Copy());
Assert.Equal(2.2933d, System.Math.Round(cost, 4));
Assert.Equal(1.6702d, System.Math.Round(theta[0], 4));
Assert.Equal(2.1483d, System.Math.Round(theta[1], 4));
Assert.Equal(1.0887d, System.Math.Round(theta[2], 4));
}
public void Logistic_Regression_Test_CostFunction_2_WithRegularization()
{
Matrix X = new[, ] {
{ 8, 1, 6 },
{ 3, 5, 7 },
{ 4, 9, 2 }
};
Vector y = new Vector(new double[] { 1, 1, 0 });
Vector theta = new Vector(new double[] { 0, 1, 0 });
ICostFunction logisticCostFunction = new LogisticCostFunction()
{
X = X,
Y = y,
Lambda = 3,
Regularizer = new L2Regularizer()
};
double cost = logisticCostFunction.ComputeCost(theta.Copy());
theta = logisticCostFunction.ComputeGradient(theta.Copy());
Assert.Equal(3.6067d, System.Math.Round(cost, 4));
Assert.Equal(0.6093d, System.Math.Round(theta[0], 4));
Assert.Equal(3.8988d, System.Math.Round(theta[1], 4));
Assert.Equal(0.1131d, System.Math.Round(theta[2], 4));
}