Computes the error function.
ERF(val)
val |
- |
A scalar, series, or table. |
A scalar, series, or table.
erf(1)
returns 0.84270079.
erf(1 + i)
returns 1.316151 + 0.190453i
erfinv(erf(.2))
returns 0.2 indicating that ERF and ERFINV are inverse functions.
erf(-2..0.01..2);
xlabel("x");ylabel("erf(x)");label("Error Function");
returns 401 samples of erf(x).
The error function is defined as:
ERF is computed from the FADDEEVA function based on an algorithm developed by Steven G. Johnson. The Faddeeva function is defined as:
For a series of measurements described by a normal distribution with a standard deviation of σ and mean value of 0:
p is the probability that the error of a single measurement lies between -a and +a, for positive a.
See PROBN for an implementation of the normal probability distribution function.