public void CoulombAgreement()
{
// The individual CoulombF and CoulombG functions should agree with the Coulomb
// function that computes both.
foreach (int L in TestUtilities.GenerateIntegerValues(1, 100, 4))
{
foreach (double eta in TestUtilities.GenerateRealValues(1.0E-1, 1.0E2, 8))
{
foreach (double rho in TestUtilities.GenerateRealValues(1.0E-2, 1.0E4, 16))
{
double F = AdvancedMath.CoulombF(L, eta, rho);
double G = AdvancedMath.CoulombG(L, eta, rho);
SolutionPair s = AdvancedMath.Coulomb(L, eta, rho);
Assert.IsTrue(TestUtilities.IsNearlyEqual(F, s.FirstSolutionValue));
// We are producing NaNs for divergent G rathar than infinities
if (F == 0.0)
{
continue;
}
Assert.IsTrue(TestUtilities.IsNearlyEqual(G, s.SecondSolutionValue));
}
}
}
}
public void CoulombRhoZero()
{
// L = 0
foreach (double eta in TestUtilities.GenerateRealValues(1.0E-2, 1.0E3, 4))
{
foreach (int sign in new int[] { 1, -1 })
{
// F is zero
Assert.IsTrue(AdvancedMath.CoulombF(0, sign * eta, 0.0) == 0.0);
// G is 1/C_{\ell}(\eta), F' = C_{\ell}(eta), so product is 1
SolutionPair s = AdvancedMath.Coulomb(0, sign * eta, 0.0);
Assert.IsTrue(TestUtilities.IsNearlyEqual(s.FirstSolutionDerivative * s.SecondSolutionValue, 1.0));
Assert.IsTrue(Double.IsNegativeInfinity(s.SecondSolutionDerivative));
}
}
// L > 0
foreach (int L in TestUtilities.GenerateIntegerValues(1, 100, 4))
{
foreach (int sign in new int[] { +1, -1 })
{
foreach (double eta in TestUtilities.GenerateRealValues(1.0E-2, 1.0E3, 8))
{
// F is zero, G is infinite
Assert.IsTrue(AdvancedMath.CoulombF(L, sign * eta, 0.0) == 0.0);
Assert.IsTrue(Double.IsInfinity(AdvancedMath.CoulombG(L, sign * eta, 0.0)));
}
}
}
}
public void CoulombWronskianWithDerivatives()
{
foreach (int L in TestUtilities.GenerateIntegerValues(1, 100, 8))
{
foreach (int sign in new int[] { +1, -1 })
{
foreach (double eta in TestUtilities.GenerateRealValues(1.0E-1, 1.0E2, 16))
{
foreach (double rho in TestUtilities.GenerateRealValues(1.0E-2, 1.0E4, 32))
{
SolutionPair s = AdvancedMath.Coulomb(L, eta, rho);
// If F and G underflow and overflow, skip check
if (s.FirstSolutionValue == 0.0)
{
continue;
}
Assert.IsTrue(TestUtilities.IsSumNearlyEqual(
s.FirstSolutionDerivative * s.SecondSolutionValue, -s.FirstSolutionValue * s.SecondSolutionDerivative, 1.0,
TestUtilities.TargetPrecision * 10.0
));
}
}
}
}
}
public void CoulombAgreement()
{
// The individual CoulombF and CoulombG functions should agree with the Coulomb
// function that computes both.
foreach (int L in TestUtilities.GenerateIntegerValues(1, 100, 8))
{
foreach (int sign in new int[] { +1, -1 })
{
foreach (double eta in TestUtilities.GenerateRealValues(1.0E-1, 1.0E2, 16))
{
foreach (double rho in TestUtilities.GenerateRealValues(1.0E-2, 1.0E4, 32))
{
double F = AdvancedMath.CoulombF(L, sign * eta, rho);
double G = AdvancedMath.CoulombG(L, sign * eta, rho);
SolutionPair s = AdvancedMath.Coulomb(L, sign * eta, rho);
// Deep in transition region, there are cases where we integrate for full solution pair in order to get G,
// then use Wronskian from that G to get F. But if we are just computing F, we use series to get a different
// (and more accurate) answer. So we relax agreement criteria a bit. Eventually, would be great to do
// series for G everywhere we can do series for F.
if (!TestUtilities.IsNearlyEqual(F, s.FirstSolutionValue, 4.0 * TestUtilities.TargetPrecision))
{
Console.WriteLine($"L={L} eta={eta} rho={rho} F={F} s.F={s.FirstSolutionValue} b={Double.IsNaN(s.SecondSolutionDerivative)}");
}
Assert.IsTrue(TestUtilities.IsNearlyEqual(F, s.FirstSolutionValue, 4.0 * TestUtilities.TargetPrecision));
Assert.IsTrue(TestUtilities.IsNearlyEqual(G, s.SecondSolutionValue));
}
}
}
}
}
public static void ComputeSpecialFunctions()
{
// Compute the value x at which erf(x) is just 10^{-15} from 1.
double x = AdvancedMath.InverseErfc(1.0E-15);
// The Gamma function at 1/2 is sqrt(pi)
double y = AdvancedMath.Gamma(0.5);
// Compute a Coulomb Wave Function in the quantum tunneling region
SolutionPair s = AdvancedMath.Coulomb(2, 4.5, 3.0);
// Compute the Reimann Zeta function at a complex value
Complex z = AdvancedComplexMath.RiemannZeta(new Complex(0.75, 6.0));
// Compute the 100th central binomial coefficient
double c = AdvancedIntegerMath.BinomialCoefficient(100, 50);
}
public void CoulombAtOrigin()
{
// F is zero at origin for all L and eta
Assert.IsTrue(AdvancedMath.CoulombF(0, -1.2, 0.0) == 0.0);
Assert.IsTrue(AdvancedMath.CoulombF(5, 4.3, 0.0) == 0.0);
// For L = 0, F' and G are finite, non-zero, and related
SolutionPair s = AdvancedMath.Coulomb(0, 5.6, 0.0);
Assert.IsTrue(s.FirstSolutionValue == 0.0);
Assert.IsTrue(TestUtilities.IsNearlyEqual(
s.FirstSolutionDerivative * s.SecondSolutionValue,
1.0
));
Assert.IsTrue(s.SecondSolutionDerivative == Double.NegativeInfinity);
}
public void CoulombWronskian()
{
foreach (int L in TestUtilities.GenerateIntegerValues(1, 100, 8))
{
foreach (double eta in TestUtilities.GenerateRealValues(1.0E-1, 1.0E2, 16))
{
foreach (double rho in TestUtilities.GenerateRealValues(1.0E-2, 1.0E4, 32))
{
SolutionPair rp = AdvancedMath.Coulomb(L, eta, rho);
Debug.WriteLine("{0} {1} {2} : {3} {4} {5} {6} : {7}",
L, eta, rho,
rp.FirstSolutionValue, rp.FirstSolutionDerivative,
rp.SecondSolutionValue, rp.SecondSolutionDerivative,
rp.FirstSolutionDerivative * rp.SecondSolutionValue - rp.FirstSolutionValue * rp.SecondSolutionDerivative
);
// if F and G underflow and overflow, skip check
if (rp.FirstSolutionValue == 0.0)
{
continue;
}
Assert.IsTrue(TestUtilities.IsSumNearlyEqual(
rp.FirstSolutionDerivative * rp.SecondSolutionValue, -rp.FirstSolutionValue * rp.SecondSolutionDerivative, 1.0,
TestUtilities.TargetPrecision * 10.0
));
SolutionPair rm = AdvancedMath.Coulomb(L, -eta, rho);
Debug.WriteLine("{0} {1} {2} : {3} {4} {5} {6} : {7}",
L, -eta, rho,
rm.FirstSolutionValue, rm.FirstSolutionDerivative,
rm.SecondSolutionValue, rm.SecondSolutionDerivative,
rm.FirstSolutionDerivative * rm.SecondSolutionValue - rm.FirstSolutionValue * rm.SecondSolutionDerivative
);
Assert.IsTrue(TestUtilities.IsSumNearlyEqual(
rm.FirstSolutionDerivative * rm.SecondSolutionValue, -rm.FirstSolutionValue * rm.SecondSolutionDerivative, 1.0,
TestUtilities.TargetPrecision * 10.0
));
}
}
}
}
private void CoulombRecursionTest(int L, double eta, double rho)
{
SolutionPair sm = AdvancedMath.Coulomb(L - 1, eta, rho);
SolutionPair s0 = AdvancedMath.Coulomb(L, eta, rho);
SolutionPair sp = AdvancedMath.Coulomb(L + 1, eta, rho);
double eps = 8.0 * TestUtilities.TargetPrecision;
// Relating u_{L}' to u_{L-1} and u_{L}
Assert.IsTrue(TestUtilities.IsSumNearlyEqual(
MoreMath.Hypot(L, eta) * sm.FirstSolutionValue,
-(L * L / rho + eta) * s0.FirstSolutionValue,
L * s0.FirstSolutionDerivative,
eps
));
Assert.IsTrue(TestUtilities.IsSumNearlyEqual(
MoreMath.Hypot(L, eta) * sm.SecondSolutionValue,
-(L * L / rho + eta) * s0.SecondSolutionValue,
L * s0.SecondSolutionDerivative,
eps
));
// Relating u_{L}' to u_{L} and u_{L+1}
// Relating u_{L+1}, u_{L}, u_{L-1}
Assert.IsTrue(TestUtilities.IsSumNearlyEqual(
(2 * L + 1) * (eta + L * (L + 1) / rho) * s0.FirstSolutionValue,
-(L + 1) * MoreMath.Hypot(L, eta) * sm.FirstSolutionValue,
L * MoreMath.Hypot(L + 1, eta) * sp.FirstSolutionValue,
eps
));
Assert.IsTrue(TestUtilities.IsSumNearlyEqual(
(2 * L + 1) * (eta + L * (L + 1) / rho) * s0.SecondSolutionValue,
-(L + 1) * MoreMath.Hypot(L, eta) * sm.SecondSolutionValue,
L * MoreMath.Hypot(L + 1, eta) * sp.SecondSolutionValue,
eps
));
}
public static void Main(string[] args)
{
// calculate the factorials of 0 through 10
for (long counter = 0; counter <= 10; ++counter)
{
Console.WriteLine("{0}! = {1}", counter, Factorial(counter));
}
// Compute the value x at which erf(x) is just 10^{-15} from 1.
double x = AdvancedMath.InverseErfc(1.0E-15);
Console.WriteLine("\n{0}", x);
// The Gamma function at 1/2 is sqrt(pi)
double y = AdvancedMath.Gamma(0.5);
Console.WriteLine("\nThe Gamma function at 1/2 is sqrt(pi) = {0}", y);
// Compute a Coulomb Wave Function in the quantum tunneling region
SolutionPair s = AdvancedMath.Coulomb(2, 4.5, 3.0);
Console.WriteLine("\nCompute a Coulomb Wave Function in the quantum tunneling region = {0}", s);
// Compute the Reimann Zeta function at a complex value
Complex z = AdvancedComplexMath.RiemannZeta(new Complex(0.75, 6.0));
Console.WriteLine("\nCompute the Reimann Zeta function at a complex value = {0}", z);
// Compute the 100th central binomial coefficient
double c = AdvancedIntegerMath.BinomialCoefficient(5, 2);
Console.WriteLine("\n{0}", c);
Console.WriteLine("\nTecle qualquer tecla para finalizar...");
Console.ReadKey();
} // end Main
