[TestCase(0, 1E6, 1E6, 0.99999975000000000003, 2.5000006250003125000E-7, 8)] // cf. BesselI(0, 1e6 + 1e6 j) = 7.4E434290 - 6.9E434290 j and BesselI(1, 1e6 + 1e6 j) = 7.4E434290 - 6.9E434290 j public void BesselIRatioExact(int n, double zr, double zi, double cyr, double cyi, int decimalPlaces) { var z = new Complex(zr, zi); var actual = SpecialFunctions.BesselIScaled(n + 1, z) / SpecialFunctions.BesselIScaled(n, z); AssertHelpers.AlmostEqualRelative(new Complex(cyr, cyi), actual, decimalPlaces); }