/// <summary>
/// Computes RisingFactorial(x:[-170...170], n:[-170...170]) using big integers
/// </summary>
/// <returns></returns>
public TestCase2[] GetRisingFactorialIntData()
{
double DoubleMinNormal = Math.Pow(2, -1022);
int Len = Math2.FactorialTable.Length - 1;
var data = new List <TestCase2>(4 * Len * Len);
for (int x = -Len; x < Len; x++)
{
for (int n = -Len; n < Len; n++)
{
// divide by zero
if (x > 0 && x + n <= 0)
{
continue;
}
// our big integer routines don't work well with denorms
double result = BigInt.FactorialRising((BigInteger)x, n);
if (Math.Abs(result) < DoubleMinNormal)
{
result = 0;
}
data.Add(new TestCase2(x, n, result));
}
}
return(data.ToArray());
}