Please reply to the mail list, not me. That is just a series expansion (i.e. numerical approximation) of erfc. I’m not sure why it is used–either because it is faster or because a built-in erfc wasn’t available at the time the original code was written.
Stan
Please reply to the mail list, not me. That is just a series expansion (i.e. numerical approximation) of erfc. I’m not sure why it is used–either because it is faster or because a built-in erfc wasn’t available at the time the original code was written.
I think both. But I am also confident, that the coefficients are taken from Abramovitz & Stegun, Handbook of mathematical functions.
The way the expression is written is just using Horner’s rule.
Axel