public void Constructor()
{
var d = new FastGaussianDistributionF(2, 3);
Assert.AreEqual(2, d.ExpectedValue);
Assert.AreEqual(3, d.StandardDeviation);
}
public void Test1()
{
var d = new FastGaussianDistributionF();
Assert.AreEqual(0, d.ExpectedValue);
Assert.AreEqual(1, d.StandardDeviation);
var random = new Random(123);
// Create 100 random values and check if they are valid.
for (int i = 0; i < 100; i++)
{
float r = d.Next(random);
Assert.IsTrue(-3 <= r);
Assert.IsTrue(r <= 3);
}
d.ExpectedValue = 100;
d.StandardDeviation = 10;
for (int i = 0; i < 100; i++)
{
float r = d.Next(random);
Assert.IsTrue(70f <= r);
Assert.IsTrue(r <= 130);
}
}
public void Test1()
{
var d = new FastGaussianDistributionF();
Assert.AreEqual(0, d.ExpectedValue);
Assert.AreEqual(1, d.StandardDeviation);
var random = new Random(123);
// Create 100 random values and check if they are valid.
for (int i=0; i<100; i++)
{
float r = d.Next(random);
Assert.IsTrue(-3 <= r);
Assert.IsTrue(r <= 3);
}
d.ExpectedValue = 100;
d.StandardDeviation = 10;
for (int i = 0; i < 100; i++)
{
float r = d.Next(random);
Assert.IsTrue(70f <= r);
Assert.IsTrue(r <= 130);
}
}
// Creates texture containing h0.
private void InitializeH0Spectrum(GraphicsDevice graphicsDevice)
{
// See also comments in InitializeCpuFft().
var n = TextureSize;
var h0 = new Vector2F[(n + 1) * (n + 1)];
var random = new Random(Seed);
var distribution = new FastGaussianDistributionF(0, 1);
// TODO: Do not compute the inner parts of this h0 and _h0 in PerformCpuFft() twice.
float oneOverSqrt2 = 1 / (float)Math.Sqrt(2);
for (int i = 0; i <= n / 2; i++)
{
for (int x = -i; x <= i; x++)
{
for (int y = -i; y <= i; y++)
{
if (x > -i && x < i && y > -i && y < i)
{
y = i - 1;
continue;
}
Vector2F xi = new Vector2F(distribution.Next(random), distribution.Next(random));
Vector2F k = new Vector2F(GetKx(x), GetKy(y));
//h0[GetIndex(x, n), GetIndex(y, n)] =
h0[GetIndex(x, n) + (n + 1) * GetIndex(y, n)] =
xi * (oneOverSqrt2 * (float)Math.Sqrt(GetPhillipsSpectrum(k)));
}
}
}
H0Spectrum.SafeDispose();
H0Spectrum = new Texture2D(graphicsDevice, n + 1, n + 1, false, SurfaceFormat.Vector2);
H0Spectrum.SetData(h0);
}
private void InitializeCpuFft()
{
var n = CpuSize;
if (_h0 == null || _h0.GetLength(0) != n + 1)
_h0 = new Vector2F[n + 1, n + 1];
var random = new Random(Seed);
var distribution = new FastGaussianDistributionF(0, 1);
// Create h0.
float oneOverSqrt2 = 1 / (float)Math.Sqrt(2);
// Instead of simply iterating over all elements of h0, we fill it in concentric
// rectangles from the center to the border. This way, a simulation with N = 16
// will use the same frequencies as a simulation with N = 32 because the inner h0s
// are initialized with the same random numbers!!!
for (int i = 0; i <= n / 2; i++)
{
for (int x = -i; x <= i; x++)
{
for (int y = -i; y <= i; y++)
{
// Skip elements of the inner part which was already initialized.
if (x > -i && x < i && y > -i && y < i)
{
y = i - 1;
continue;
}
Vector2F xi = new Vector2F(distribution.Next(random), distribution.Next(random));
Vector2F k = new Vector2F(GetKx(x), GetKy(y));
_h0[GetIndex(x, n), GetIndex(y, n)] =
xi * (oneOverSqrt2 * (float)Math.Sqrt(GetPhillipsSpectrum(k)));
}
}
}
if (_oneOverKLength == null || _oneOverKLength.GetLength(0) != n)
{
_oneOverKLength = new float[n, n];
_omega = new float[n, n];
_h = new Vector2F[n, n];
_N = new Vector2F[n, n];
_D = new Vector2F[n, n];
}
// Create _oneOverKLength and _omega
for (int x = -n / 2; x < n / 2; x++)
{
for (int y = -n / 2; y < n / 2; y++)
{
float length = new Vector2F(GetKx(x), GetKy(y)).Length;
_omega[GetIndex(x, n), GetIndex(y, n)] = GetOmega(length);
// Avoid division by zero.
if (length < 1e-8f)
length = 1e-8f;
_oneOverKLength[GetIndex(x, n), GetIndex(y, n)] = 1 / length;
}
}
}
public void Constructor()
{
var d = new FastGaussianDistributionF(2, 3);
Assert.AreEqual(2, d.ExpectedValue);
Assert.AreEqual(3, d.StandardDeviation);
}
// Creates texture containing h0.
private void InitializeH0Spectrum(GraphicsDevice graphicsDevice)
{
// See also comments in InitializeCpuFft().
var n = TextureSize;
var h0 = new Vector2F[(n + 1) * (n + 1)];
var random = new Random(Seed);
var distribution = new FastGaussianDistributionF(0, 1);
// TODO: Do not compute the inner parts of this h0 and _h0 in PerformCpuFft() twice.
float oneOverSqrt2 = 1 / (float)Math.Sqrt(2);
for (int i = 0; i <= n / 2; i++)
{
for (int x = -i; x <= i; x++)
{
for (int y = -i; y <= i; y++)
{
if (x > -i && x < i && y > -i && y < i)
{
y = i - 1;
continue;
}
Vector2F xi = new Vector2F(distribution.Next(random), distribution.Next(random));
Vector2F k = new Vector2F(GetKx(x), GetKy(y));
//h0[GetIndex(x, n), GetIndex(y, n)] =
h0[GetIndex(x, n) + (n + 1) * GetIndex(y, n)] =
xi * (oneOverSqrt2 * (float)Math.Sqrt(GetPhillipsSpectrum(k)));
}
}
}
H0Spectrum.SafeDispose();
H0Spectrum = new Texture2D(graphicsDevice, n + 1, n + 1, false, SurfaceFormat.Vector2);
H0Spectrum.SetData(h0);
}
private void InitializeCpuFft()
{
var n = CpuSize;
if (_h0 == null || _h0.GetLength(0) != n + 1)
_h0 = new Vector2F[n + 1, n + 1];
var random = new Random(Seed);
var distribution = new FastGaussianDistributionF(0, 1);
// Create h0.
float oneOverSqrt2 = 1 / (float)Math.Sqrt(2);
// Instead of simply iterating over all elements of h0, we fill it in concentric
// rectangles from the center to the border. This way, a simulation with N = 16
// will use the same frequencies as a simulation with N = 32 because the inner h0s
// are initialized with the same random numbers!!!
for (int i = 0; i <= n / 2; i++)
{
for (int x = -i; x <= i; x++)
{
for (int y = -i; y <= i; y++)
{
// Skip elements of the inner part which was already initialized.
if (x > -i && x < i && y > -i && y < i)
{
y = i - 1;
continue;
}
Vector2F xi = new Vector2F(distribution.Next(random), distribution.Next(random));
Vector2F k = new Vector2F(GetKx(x), GetKy(y));
_h0[GetIndex(x, n), GetIndex(y, n)] =
xi * (oneOverSqrt2 * (float)Math.Sqrt(GetPhillipsSpectrum(k)));
}
}
}
if (_oneOverKLength == null || _oneOverKLength.GetLength(0) != n)
{
_oneOverKLength = new float[n, n];
_omega = new float[n, n];
_h = new Vector2F[n, n];
_N = new Vector2F[n, n];
_D = new Vector2F[n, n];
}
// Create _oneOverKLength and _omega
for (int x = -n / 2; x < n / 2; x++)
{
for (int y = -n / 2; y < n / 2; y++)
{
float length = new Vector2F(GetKx(x), GetKy(y)).Length;
_omega[GetIndex(x, n), GetIndex(y, n)] = GetOmega(length);
// Avoid division by zero.
if (length < 1e-8f)
length = 1e-8f;
_oneOverKLength[GetIndex(x, n), GetIndex(y, n)] = 1 / length;
}
}
}
