/// <summary>
/// Computes the anisotropy function using bilinear interpolation from Ir192 source
/// </summary>
/// <param name="radialDistanceMm">radial distance in mm</param>
/// <param name="polarAngle">polar angle</param>
/// <returns>anisotropy factor</returns>
public static double ComputeAnisotropy(double radialDistanceMm, double polarAngle)
{
var polar = new PolarPosition(radialDistanceMm, polarAngle);
return(Ir192AnisotropyCalculator.Compute(polar));
}
/// <summary>
/// Computes the anisotropy function using bilinear interpolation.
/// </summary>
/// <param name="radialDistanceMm"></param>
/// <param name="polarAngle"></param>
/// <returns></returns>
public static double Compute(PolarPosition polar)
{
if (!areTablesPopulated)
{
PopulateTable();
}
double rCm = polar.Distance_mm / 10.0;
double angleDeg = 180.0 * polar.Angle_rad / Math.PI;
if (rCm < anisotropyFunctionTableRadialDistanceCm[0] || rCm >= anisotropyFunctionTableRadialDistanceCm[anisotropyFunctionTableRadialDistanceCm.Length - 1])
{
throw new ArgumentOutOfRangeException("radialDistanceMm", "Distance is not within range of the anisotropy function table.");
}
if (angleDeg < 0.0 || angleDeg > 180.0)
{
throw new ArgumentOutOfRangeException("polarAngle", "Invalid polar angle - polar angle must be in range 0-180 degrees.");
}
int j = 0;
if (rCm >= anisotropyFunctionTableRadialDistanceCm[anisotropyFunctionTableRadialDistanceCm.Length - 1])
{
j = anisotropyFunctionTableRadialDistanceCm.Length - 2;
}
else if (rCm > anisotropyFunctionTableRadialDistanceCm[0])
{
j = Array.FindLastIndex(anisotropyFunctionTableRadialDistanceCm, r => r < rCm);
}
int i = 0;
if (angleDeg >= anisotropyFunctionTablePolarAngleDeg[anisotropyFunctionTablePolarAngleDeg.Length - 1])
{
i = anisotropyFunctionTablePolarAngleDeg.Length - 2;
}
else if (angleDeg > anisotropyFunctionTablePolarAngleDeg[0])
{
i = Array.FindLastIndex(anisotropyFunctionTablePolarAngleDeg, a => a < angleDeg);
}
if (Double.IsNaN(anisotropyFunctionTableValue[i, j]) || Double.IsNaN(anisotropyFunctionTableValue[i, j + 1]) || Double.IsNaN(anisotropyFunctionTableValue[i + 1, j]) || Double.IsNaN(anisotropyFunctionTableValue[i + 1, j + 1]))
{
throw new ArgumentOutOfRangeException("radialDistanceMm", "Interpolation of anisotropy function requires data points that are not defined - calculation point is inside the source.");
}
double delta = rCm - anisotropyFunctionTableRadialDistanceCm[j];
double slope = (anisotropyFunctionTableValue[i, j + 1] - anisotropyFunctionTableValue[i, j]) / (anisotropyFunctionTableRadialDistanceCm[j + 1] - anisotropyFunctionTableRadialDistanceCm[j]);
double result1 = slope * delta + anisotropyFunctionTableValue[i, j];
delta = rCm - anisotropyFunctionTableRadialDistanceCm[j];
slope = (anisotropyFunctionTableValue[i + 1, j + 1] - anisotropyFunctionTableValue[i + 1, j]) / (anisotropyFunctionTableRadialDistanceCm[j + 1] - anisotropyFunctionTableRadialDistanceCm[j]);
double result2 = slope * delta + anisotropyFunctionTableValue[i + 1, j];
delta = angleDeg - anisotropyFunctionTablePolarAngleDeg[i];
slope = (result2 - result1) / (anisotropyFunctionTablePolarAngleDeg[i + 1] - anisotropyFunctionTablePolarAngleDeg[i]);
double result = slope * delta + result1;
return(result);
}
/// <summary>
/// Computes the anisotropy function using bilinear interpolation from Ir192 source
/// </summary>
/// <param name="polar">the polar position of desired calc</param>
/// <returns>anisotropy factor</returns>
public static double ComputeAnisotropy(PolarPosition polar)
{
return(Ir192AnisotropyCalculator.Compute(polar));
}
