public void TestLineSearchDeterminesSaneStepLength2()
{
var objectiveFunction = new QuadraticFunction2();
// given
var testX = new double[] { -2 };
var testValueX = objectiveFunction.ValueAt(testX);
var testGradX = objectiveFunction.GradientAt(testX);
var testDirection = new double[] { 1 };
// when
var lsr = LineSearchResult.GetInitialObject(testValueX, testGradX, testX);
LineSearch.DoLineSearch(objectiveFunction, testDirection, lsr, 1.0);
var stepSize = lsr.StepSize;
// then
Assert.True(Tolerance < stepSize && stepSize <= 1);
}
public void TestLineSearchFailsAtMinimum1()
{
var objectiveFunction = new QuadraticFunction2();
// given
double[] testX = { 0 };
var testValueX = objectiveFunction.ValueAt(testX);
var testGradX = objectiveFunction.GradientAt(testX);
double[] testDirection = { -1 };
// when
var lsr = LineSearchResult.GetInitialObject(testValueX, testGradX, testX);
LineSearch.DoLineSearch(objectiveFunction, testDirection, lsr, 1.0);
var stepSize = lsr.StepSize;
// then
Assert.False(Tolerance < stepSize && stepSize <= 1);
Assert.AreEqual(0.0, stepSize, Tolerance);
}
