erfe

Evaluates a scaled function related to erfc(z).

Synopsis

#include <imsl.h>

f_complex imsl_c_erfe (f_complex z)

The type double complex function is imsl_z_erfe.

Required Arguments

f_complex z (Input)
Complex argument for which the function value is desired.

Return Value

Complex scaled function value related to erfc(z).

Description

Function imsl_c_erfe is defined to be

 

Let b =imsl_f_machine(2) be the largest floating-point number. The argument z must satisfy

 

or else the value returned is zero. If the argument z does not satisfy

(ℑz)2 - (ℜz)2 ≤log b,

then b is returned. All other arguments are legal (Gautschi 1969, 1970).

For more information, see the description for imsl_f_machine.

Example

In this example, imsl_c_erfe(2.5 +2.5i) is computed and printed.

 

#include <imsl.h>

#include <stdio.h>

 

int main()

{

f_complex value, z;

 

z = imsl_cf_convert(2.5, 2.5);

value = imsl_c_erfe(z);

printf("\n erfe(%2.3f + %2.3fi) = %2.3f + %2.3fi \n",

z.re, z.im, value.re, value.im);

}

Output

 

erfe(2.500 +2.500i) = 0.117 +0.108i