public void TestRidgeShapes()
{
var rng = new Random(0);
const int nSamples = 5;
const int nFeatures = 10;
Matrix x = DenseMatrix.CreateRandom(nSamples, nFeatures, new Normal {
RandomSource = rng
});
Vector y = DenseVector.CreateRandom(nSamples, new Normal {
RandomSource = rng
});
Matrix Y = DenseMatrix.OfColumns(y.Count, 2, new[] { y, y.Add(1) });
var ridge = new RidgeRegression();
ridge.Fit(x, y);
Assert.AreEqual(ridge.Coef.Shape(), Tuple.Create(1, nFeatures));
Assert.AreEqual(ridge.Intercept.Count, 1);
ridge.Fit(x, MatrixExtensions.ToColumnMatrix(y));
Assert.AreEqual(ridge.Coef.Shape(), Tuple.Create(1, nFeatures));
Assert.AreEqual(ridge.Intercept.Count, 1);
ridge.Fit(x, Y);
Assert.AreEqual(ridge.Coef.Shape(), Tuple.Create(2, nFeatures));
Assert.AreEqual(ridge.Intercept.Count, 2);
}
public void TestToyRidgeObject()
{
var x = DenseMatrix.OfArray(new double[, ] {
{ 1 }, { 2 }
});
var y = new DenseVector(new double[] { 1, 2 });
var clf = new RidgeRegression(alpha: 0.0);
clf.Fit(x, y);
var xTest = DenseMatrix.OfArray(new double[, ] {
{ 1 }, { 2 }, { 3 }, { 4 }
});
Assert.AreEqual((clf.Predict(xTest) -
DenseMatrix.OfArray(new double[, ] {
{ 1 }, { 2 }, { 3 }, { 4 }
})).FrobeniusNorm(), 0.0, 1e-10);
Assert.AreEqual(clf.Coef.RowCount, 1);
var y1 = DenseMatrix.OfColumns(y.Count, 2, new[] { y, y });
clf.Fit(x, y1);
//todo: what does this test do?
}
private double?TestRidgeDiabetes(Func <Matrix <double>, Matrix <double> > filter)
{
var ridge = new RidgeRegression(fitIntercept: false);
ridge.Fit(filter(xDiabetes), yDiabetes);
return(Math.Round(ridge.Score(filter(xDiabetes), yDiabetes), 5));
}
public void TestRidge()
{
var rng = new Random(0);
const double alpha = 1.0;
foreach (var solver in new[] { RidgeSolver.Svd, RidgeSolver.DenseCholesky, RidgeSolver.Lsqr })
{
// With more samples than features
int nSamples = 6;
int nFeatures = 5;
var normal = new Normal { RandomSource = rng };
Vector y = DenseVector.CreateRandom(nSamples, normal);
Matrix x = DenseMatrix.CreateRandom(nSamples, nFeatures, normal);
var ridge = new RidgeRegression(alpha: alpha, solver: solver);
ridge.Fit(x, y);
Assert.AreEqual(ridge.Coef.Row(0).Count, x.ColumnCount);
Assert.IsTrue(ridge.Score(x, y) > 0.47);
ridge.Fit(x, y, sampleWeight: DenseVector.Create(nSamples, i => 1.0));
Assert.IsTrue(ridge.Score(x, y) > 0.47);
// With more features than samples
nSamples = 5;
nFeatures = 10;
y = DenseVector.CreateRandom(nSamples, normal);
x = DenseMatrix.CreateRandom(nSamples, nFeatures, normal);
ridge = new RidgeRegression(alpha: alpha, solver: solver);
ridge.Fit(x, y);
Assert.IsTrue(ridge.Score(x, y) > 0.9);
ridge.Fit(x, y, sampleWeight: DenseVector.Create(nSamples, i => 1.0));
Assert.IsTrue(ridge.Score(x, y) > 0.9);
}
}
public void TestRidgeSampleWeights()
{
var rng = new Random(0);
const double alpha = 1.0;
foreach (var solver in new[] { RidgeSolver.Svd, RidgeSolver.DenseCholesky, RidgeSolver.Lsqr })
{
var tests = new[] { new[] { 6, 5 }, new[] { 5, 10 } };
foreach (var test in tests)
{
int nSamples = test[0];
int nFeatures = test[1];
Vector y = DenseVector.CreateRandom(nSamples, new Normal {
RandomSource = rng
});
Matrix x = DenseMatrix.CreateRandom(nSamples, nFeatures, new Normal {
RandomSource = rng
});
Vector sampleWeight = DenseVector.CreateRandom(nSamples, new ContinuousUniform(1, 2));
var ridgeRegression = new RidgeRegression(alpha: alpha, solver: solver, fitIntercept: false);
ridgeRegression.Fit(x, y, sampleWeight);
var coefs = ridgeRegression.Coef.Column(0);
// Sample weight can be implemented via a simple rescaling
// for the square loss
var regression2 = new RidgeRegression(alpha, solver: solver, fitIntercept: false);
regression2.Fit(
x.MulColumnVector(sampleWeight.Sqrt()),
y.PointwiseMultiply(sampleWeight.Sqrt()));
var coefs2 = regression2.Coef.Column(0);
Assert.IsTrue(coefs.AlmostEquals(coefs2));
}
}
}
public void FitPredictLSQR_WithoutInterceptAndWithRandomData_ReturnsCorrectResult()
{
var(x, y, theta) = Generate(intercept: false);
var(xTrain, yTrain, xTest, yTest) = ModelValidation.TrainTestSplit(x, y, 0.5);
var estimator = new RidgeRegression(intercept: false, method: RidgeRegressionMethod.LSQR).Fit(x, y);
var yTrainPred = estimator.Predict(xTrain);
var yTestPred = estimator.Predict(xTest);
FloatingPointAssert.Equal(theta, estimator.Weights, 1e-3);
FloatingPointAssert.Equal(yTrain, yTrainPred, 1e-2);
FloatingPointAssert.Equal(yTest, yTestPred, 1e-2);
}
public void RidgeRegressionSample()
{
var clf = new RidgeRegression(alpha: 0.5);
clf.Fit(new[, ] {
{ 0.0, 0.0 }, { 0.0, 0.0 }, { 1.0, 1.0 }
}, new[] { 0.0, 0.1, 1.0 });
Console.WriteLine(clf.Coef);
Console.WriteLine(clf.Intercept);
var prediction = clf.Predict(new[] { 5.0, 6.0 });
Console.WriteLine(prediction);
}
private double?TestTolerance(Func <Matrix <double>, Matrix <double> > filter)
{
var ridge = new RidgeRegression(tol: 1e-5);
ridge.Fit(filter(xDiabetes), yDiabetes);
double score = ridge.Score(filter(xDiabetes), yDiabetes);
var ridge2 = new RidgeRegression(tol: 1e-3);
ridge2.Fit(filter(xDiabetes), yDiabetes);
double score2 = ridge2.Score(filter(xDiabetes), yDiabetes);
Assert.IsTrue(score >= score2);
return(null);
}
private double?TestMultiRidgeDiabetes(Func <Matrix <double>, Matrix <double> > filter)
{
// simulate several responses
Matrix y = yDiabetes.HStack(yDiabetes);
int nFeatures = xDiabetes.ColumnCount;
var ridge = new RidgeRegression(fitIntercept: false);
ridge.Fit(filter(xDiabetes), y);
Assert.AreEqual(ridge.Coef.Shape(), Tuple.Create(2, nFeatures));
Matrix <double> yPred = ridge.Predict(filter(xDiabetes));
ridge.Fit(filter(xDiabetes), yDiabetes);
var yPred1 = ridge.Predict(filter(xDiabetes));
Assert.IsTrue(yPred1.HStack(yPred1).AlmostEquals(yPred));
return(null);
}
public void TestRidgeIntercept()
{
var rng = new Random(0);
const int nSamples = 5;
const int nFeatures = 10;
Matrix x = DenseMatrix.CreateRandom(nSamples, nFeatures, new Normal {
RandomSource = rng
});
Vector y = DenseVector.CreateRandom(nSamples, new Normal {
RandomSource = rng
});
Matrix y1 = DenseMatrix.OfColumns(y.Count, 2, new[] { y, y.Add(1) });
var ridge = new RidgeRegression();
ridge.Fit(x, y);
var intercept = ridge.Intercept;
ridge.Fit(x, y1);
Assert.AreEqual(ridge.Intercept[0], intercept[0], 1e-10);
Assert.AreEqual(ridge.Intercept[1], intercept[0] + 1, 1e-10);
}
public void TestRidge()
{
var rng = new Random(0);
const double alpha = 1.0;
foreach (var solver in new[] { RidgeSolver.Svd, RidgeSolver.DenseCholesky, RidgeSolver.Lsqr })
{
// With more samples than features
int nSamples = 6;
int nFeatures = 5;
var normal = new Normal {
RandomSource = rng
};
Vector y = DenseVector.CreateRandom(nSamples, normal);
Matrix x = DenseMatrix.CreateRandom(nSamples, nFeatures, normal);
var ridge = new RidgeRegression(alpha: alpha, solver: solver);
ridge.Fit(x, y);
Assert.AreEqual(ridge.Coef.Row(0).Count, x.ColumnCount);
Assert.IsTrue(ridge.Score(x, y) > 0.47);
ridge.Fit(x, y, sampleWeight: DenseVector.Create(nSamples, i => 1.0));
Assert.IsTrue(ridge.Score(x, y) > 0.47);
// With more features than samples
nSamples = 5;
nFeatures = 10;
y = DenseVector.CreateRandom(nSamples, normal);
x = DenseMatrix.CreateRandom(nSamples, nFeatures, normal);
ridge = new RidgeRegression(alpha: alpha, solver: solver);
ridge.Fit(x, y);
Assert.IsTrue(ridge.Score(x, y) > 0.9);
ridge.Fit(x, y, sampleWeight: DenseVector.Create(nSamples, i => 1.0));
Assert.IsTrue(ridge.Score(x, y) > 0.9);
}
}
public void TestRidgeVsLstsq()
{
var random = new Random(0);
// we need more samples than features
const int nSamples = 5;
const int nFeatures = 4;
var y = DenseVector.CreateRandom(nSamples, new Normal {
RandomSource = random
});
var x = DenseMatrix.CreateRandom(nSamples, nFeatures, new Normal {
RandomSource = random
});
var ridge = new RidgeRegression(alpha: 0.0, fitIntercept: false);
var ols = new LinearRegression(fitIntercept: false);
ridge.Fit(x, y);
ols.Fit(x, y);
Assert.IsTrue(ridge.Coef.AlmostEquals(ols.Coef));
ridge.Fit(x, y);
ols.Fit(x, y);
Assert.IsTrue(ridge.Coef.AlmostEquals(ols.Coef));
}
public void TestRidgeShapes()
{
var rng = new Random(0);
const int nSamples = 5;
const int nFeatures = 10;
Matrix x = DenseMatrix.CreateRandom(nSamples, nFeatures, new Normal { RandomSource = rng });
Vector y = DenseVector.CreateRandom(nSamples, new Normal { RandomSource = rng });
Matrix Y = DenseMatrix.OfColumns(y.Count, 2, new[] { y, y.Add(1) });
var ridge = new RidgeRegression();
ridge.Fit(x, y);
Assert.AreEqual(ridge.Coef.Shape(), Tuple.Create(1, nFeatures));
Assert.AreEqual(ridge.Intercept.Count, 1);
ridge.Fit(x, MatrixExtensions.ToColumnMatrix(y));
Assert.AreEqual(ridge.Coef.Shape(), Tuple.Create(1, nFeatures));
Assert.AreEqual(ridge.Intercept.Count, 1);
ridge.Fit(x, Y);
Assert.AreEqual(ridge.Coef.Shape(), Tuple.Create(2, nFeatures));
Assert.AreEqual(ridge.Intercept.Count, 2);
}
public void TestToyRidgeObject()
{
var x = DenseMatrix.OfArray(new double[,] { { 1 }, { 2 } });
var y = new DenseVector(new double[] { 1, 2 });
var clf = new RidgeRegression(alpha: 0.0);
clf.Fit(x, y);
var xTest = DenseMatrix.OfArray(new double[,] { { 1 }, { 2 }, { 3 }, { 4 } });
Assert.AreEqual((clf.Predict(xTest) -
DenseMatrix.OfArray(new double[,] { { 1 }, { 2 }, { 3 }, { 4 } })).FrobeniusNorm(), 0.0, 1e-10);
Assert.AreEqual(clf.Coef.RowCount, 1);
var y1 = DenseMatrix.OfColumns(y.Count, 2, new[] { y, y });
clf.Fit(x, y1);
//todo: what does this test do?
}
public void TestRidgeVsLstsq()
{
var random = new Random(0);
// we need more samples than features
const int nSamples = 5;
const int nFeatures = 4;
var y = DenseVector.CreateRandom(nSamples, new Normal { RandomSource = random });
var x = DenseMatrix.CreateRandom(nSamples, nFeatures, new Normal { RandomSource = random });
var ridge = new RidgeRegression(alpha: 0.0, fitIntercept: false);
var ols = new LinearRegression(fitIntercept: false);
ridge.Fit(x, y);
ols.Fit(x, y);
Assert.IsTrue(ridge.Coef.AlmostEquals(ols.Coef));
ridge.Fit(x, y);
ols.Fit(x, y);
Assert.IsTrue(ridge.Coef.AlmostEquals(ols.Coef));
}
private double? TestRidgeDiabetes(Func<Matrix<double>, Matrix<double>> filter)
{
var ridge = new RidgeRegression(fitIntercept: false);
ridge.Fit(filter(xDiabetes), yDiabetes);
return Math.Round(ridge.Score(filter(xDiabetes), yDiabetes), 5);
}
public void TestRidgeIntercept()
{
var rng = new Random(0);
const int nSamples = 5;
const int nFeatures = 10;
Matrix x = DenseMatrix.CreateRandom(nSamples, nFeatures, new Normal { RandomSource = rng });
Vector y = DenseVector.CreateRandom(nSamples, new Normal { RandomSource = rng });
Matrix y1 = DenseMatrix.OfColumns(y.Count, 2, new[] { y, y.Add(1) });
var ridge = new RidgeRegression();
ridge.Fit(x, y);
var intercept = ridge.Intercept;
ridge.Fit(x, y1);
Assert.AreEqual(ridge.Intercept[0], intercept[0], 1e-10);
Assert.AreEqual(ridge.Intercept[1], intercept[0] + 1, 1e-10);
}
private double? TestMultiRidgeDiabetes(Func<Matrix<double>, Matrix<double>> filter)
{
// simulate several responses
Matrix y = yDiabetes.HStack(yDiabetes);
int nFeatures = xDiabetes.ColumnCount;
var ridge = new RidgeRegression(fitIntercept: false);
ridge.Fit(filter(xDiabetes), y);
Assert.AreEqual(ridge.Coef.Shape(), Tuple.Create(2, nFeatures));
Matrix<double> yPred = ridge.Predict(filter(xDiabetes));
ridge.Fit(filter(xDiabetes), yDiabetes);
var yPred1 = ridge.Predict(filter(xDiabetes));
Assert.IsTrue(yPred1.HStack(yPred1).AlmostEquals(yPred));
return null;
}
public void TestRidgeSampleWeights()
{
var rng = new Random(0);
const double alpha = 1.0;
foreach (var solver in new[] { RidgeSolver.Svd, RidgeSolver.DenseCholesky, RidgeSolver.Lsqr })
{
var tests = new[] { new[] { 6, 5 }, new[] { 5, 10 } };
foreach (var test in tests)
{
int nSamples = test[0];
int nFeatures = test[1];
Vector y = DenseVector.CreateRandom(nSamples, new Normal { RandomSource = rng });
Matrix x = DenseMatrix.CreateRandom(nSamples, nFeatures, new Normal { RandomSource = rng });
Vector sampleWeight = DenseVector.CreateRandom(nSamples, new ContinuousUniform(1, 2));
var ridgeRegression = new RidgeRegression(alpha: alpha, solver: solver, fitIntercept: false);
ridgeRegression.Fit(x, y, sampleWeight);
var coefs = ridgeRegression.Coef.Column(0);
// Sample weight can be implemented via a simple rescaling
// for the square loss
var regression2 = new RidgeRegression(alpha, solver: solver, fitIntercept: false);
regression2.Fit(
x.MulColumnVector(sampleWeight.Sqrt()),
y.PointwiseMultiply(sampleWeight.Sqrt()));
var coefs2 = regression2.Coef.Column(0);
Assert.IsTrue(coefs.AlmostEquals(coefs2));
}
}
}
private double? TestTolerance(Func<Matrix<double>, Matrix<double>> filter)
{
var ridge = new RidgeRegression(tol: 1e-5);
ridge.Fit(filter(xDiabetes), yDiabetes);
double score = ridge.Score(filter(xDiabetes), yDiabetes);
var ridge2 = new RidgeRegression(tol: 1e-3);
ridge2.Fit(filter(xDiabetes), yDiabetes);
double score2 = ridge2.Score(filter(xDiabetes), yDiabetes);
Assert.IsTrue(score >= score2);
return null;
}
