# ERFCX

## Purpose:

Computes the scaled complementary error function.

## Syntax:

ERFCX(val)

 val - A scalar, series, or table.

## Returns:

A scalar, series, or table.

## Example:

erfcx(1)

returns 0.427584.

## Example:

erfcx(1 + i)

returns  0.304744 - 0.208219i

## Example:

erfcx(-2..0.01..2);

xlabel("x");ylabel("erfcx(x)");label("Scaled Complementary Error Function");

returns 401 samples of erfcx(x).

## Remarks:

The scaled complementary error function is defined as:

where:

For large values of x,

ERFCX is computed from the FADDEEVA function based on an algorithm developed by Steven G. Johnson. The Faddeeva function is defined as: