build::libcerf::src::libcerf-v2.4::man::erfi(3) libcerf manual build::libcerf::src::libcerf-v2.4::man::erfi(3)

cerfi, erfi - imaginary error function

#include <cerf.h>

double _Complex cerfi ( double _Complex z );

double erfi ( double x );

The function cerfi returns an error function rotated in the complex plane, erfi(z) = -i erf(iz).

The function erfi takes a real argument and returns a real result.

The implementation of cerfi and erfi is trivially based on the functions cerf(3) and im_w_of_x(3).

Other complex error functions in libcerf: dawson(3), erfcx(3), voigt(3), w_of_z(3).

The real error function comes with recent versions of glibc, as requested by the C99 standard: erf(3).


Steven G. Johnson,,
Massachusetts Institute of Technology,
researched the numerics, and implemented the Faddeeva function.

Joachim Wuttke <>, Forschungszentrum Juelich,
reorganized the code into a library, and wrote this man page.

Please report bugs to the authors.

Copyright (c) 2012 Massachusetts Institute of Technology

Copyright (c) 2013 Forschungszentrum Juelich GmbH

Software: MIT License.

This documentation: Creative Commons Attribution Share Alike.

2023-08-02 perl v5.36.1