The Error Function

Syntax
y = erf(x)

Description
Returns the value of the error function which is defined by $${\rm erf} (x) = \frac{2}{ \sqrt{\pi} } \int_0^x \exp( - t * t ) \; {\bf d} t$$

x, y
See the possible types for a unary standard math function.

If this preprocessor symbol is true (1), and x is an AD type, this is an atomic operation .
If this preprocessor symbol is false (0), CppAD uses a fast approximation (few numerical operations) with relative error bound $4 \times 10^{-4}$; see Vedder, J.D., Simple approximations for the error function and its inverse , American Journal of Physics, v 55, n 8, 1987, p 762-3.