ERFC

The ERFC function returns the value of the complementary error function:

For real input, ERFC is computed using rational functions, as described in “Rational Chebyshev approximations for the error function,” W. J. Cody, Math. Comp., 1969, pp. 631-638. For complex input, ERFC is computed as 1 - ERF(Z).

Examples

To find the complementary error function of 0.4 and print the result, enter:

PRINT, ERFC(0.4D)

IDL prints:

0.57160764

Syntax

Result = ERFC(Z)

Return Value

The result is double-precision if the argument is double-precision, otherwise the result is floating-point. The result always has the same structure as Z. The ERFC function also accepts complex arguments.

Arguments

Z

The expression for which the complementary error function is to be evaluated. Z may be complex.

Keywords

Thread Pool Keywords

This routine is written to make use of IDL’s thread pool, which can increase execution speed on systems with multiple CPUs. The values stored in the !CPU system variable control whether IDL uses the thread pool for a given computation. In addition, you can use the thread pool keywords TPOOL_MAX_ELTS, TPOOL_MIN_ELTS, and TPOOL_NOTHREAD to override the defaults established by !CPU for a single invocation of this routine. See Thread Pool Keywords.

Version History

Pre 4.0	Introduced
5.6	Z argument accepts complex input