Special functions

Error functions and the modified Bessel function of order zero.

Like scipy.special

Special functionsError function, complementary error function and the modified Bessel function I0.

import 'package:scidart/scidart.dart';

void main() {
  print('erf(0.5) = ${erf(0.5)}');
  print('erfc(3) = ${erfc(3)}');
  // erfc keeps precision deep in the tail
  print('erfc(26.6) = ${erfc(26.6)}');
  print('I0(1) = ${besselI0(1)}');
}

Output

erf(0.5) = 0.5204998778130465
erfc(3) = 0.000022090496998585438
erfc(26.6) = 1.088512588544237e-309
I0(1) = 1.2660658480342601

erf and erfc use W. J. Cody's rational approximations and agree with scipy.special to about 1e-14 relative error. erfc keeps relative precision far into the tail, down to subnormal results.
besselI0 is the modified Bessel function of the first kind and order zero, used by the Kaiser window.
Array versions: arrayErf, arrayErfc, arrayBesselI0.