public void MakeExpressionTest()
{
Func <double, double> expected = (double x) => - Math.Pow(x, 3) / 6;
Func <double, double> actual = TaylorSeries.MakeExpression(3, 0);
Assert.AreEqual(actual(5), expected(5));
}
public void TestForCalculateExp_WhenfirstArgumentIsNegative()
{
var e = new TaylorSeries();
var actual = e.CalculateExp(-2, 4);
var expected = 1 - 2.0 / 3;
Assert.AreEqual(expected, actual);
}
public void TestForCalculateExp_WhenfirstArgumentIsZero()
{
var e = new TaylorSeries();
var actual = e.CalculateExp(0, 3);
var expected = 1;
Assert.AreEqual(expected, actual);
}
public void TestForCalculateExp_WhenBothArgumentsArePositive()
{
var e = new TaylorSeries();
var actual = e.CalculateExp(4, 3);
var expected = 13 + 64.0 / 6;
Assert.AreEqual(expected, actual);
}
public void DetermineSinSpanMaxTest()
{
Function sinFunction = new Function("sinx");
Func <double, double> series =
TaylorSeries.MakeTaylorSeries(4, 0, 1, 0);
var maxspan = TaylorSeries.DetermineSinSpanMax(sinFunction.ParsedFunc, series, 0);
Assert.AreEqual(3, maxspan);
}
public void MakeTaylorSeriesTest()
{
var actual = TaylorSeries.MakeTaylorSeries(4, 1, 1, 0);
Func <double, double> expected = (double d) => Math.Sin(1) * Math.Pow(d - 1, 0) / Function.Factorial(0)
+ Math.Cos(1) * Math.Pow(d - 1, 1) / Function.Factorial(1)
- Math.Sin(1) * Math.Pow(d - 1, 2) / Function.Factorial(2)
- Math.Cos(1) * Math.Pow(d - 1, 3) / Function.Factorial(3);
Assert.AreEqual(actual(1), expected(1));
}
public void DerivativeSectionTest()
{
var actual1 = TaylorSeries.DerivativeSection(1);
var actual2 = TaylorSeries.DerivativeSection(2);
var actual3 = TaylorSeries.DerivativeSection(3);
var actual4 = TaylorSeries.DerivativeSection(4);
Assert.AreEqual(1, actual1(0));
Assert.AreEqual(0, actual2(0));
Assert.AreEqual(-1, actual3(0));
Assert.AreEqual(0, actual4(0));
}
public void CalculateTest()
{
TaylorSeries series = new TaylorSeries(Math.Sin);
var answer = Math.Round(series.Calculate(2, 0, 1), 8);
Assert.AreEqual(0.83333333, answer);
answer = Math.Round(series.Calculate(4, 0, 1), 8);
Assert.AreEqual(0.84146825, answer);
answer = Math.Round(series.Calculate(3, 1, 2), 8);
Assert.AreEqual(0.9610378, answer);
answer = Math.Round(series.Calculate(6, 3, 5), 8);
Assert.AreEqual(-0.971033, answer);
answer = Math.Round(series.Calculate(3, -1, 2), 8);
Assert.AreEqual(4.56605536, answer);
}