---
name: "cimag"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/cimag"
---

# cimag(3)

functions to manipulate complex numbers

## NAME

**cimag**, **cimagf**, **cimagl**, **conj**, **conjf**, **conjl**, **cproj**, **cprojf**, **cprojl**, **creal**, **crealf**, **creall** – functions to manipulate complex numbers

## LIBRARY

Math Library (libm, -lm)

## SYNOPSIS

**#include \<complex.h\>**

*double*\

**cimag**(*double complex z*);

*float*\

**cimagf**(*float complex z*);

*long double*\

**cimagl**(*long double complex z*);

*double complex*\

**conj**(*double complex z*);

*float complex*\

**conjf**(*float complex z*);

*long double complex*\

**conjl**(*long double complex z*);

*double complex*\

**cproj**(*double complex z*);

*float complex*\

**cprojf**(*float complex z*);

*long double complex*\

**cprojl**(*long double complex z*);

*double*\

**creal**(*double complex z*);

*float*\

**crealf**(*float complex z*);

*long double*\

**creall**(*long double complex z*);

## DESCRIPTION

Let *a*,*+*,*b*,*\***i* denote the complex number *z*.

The **creal**() functions return the real part *a*, and the **cimag**() functions return the imaginary part *b*.

The **conj**() functions return the complex conjugate *a*,*-*,*b*,*\***i*.

The **cproj**() functions return the projection onto the Riemann sphere. If *z* contains an infinite component, then the result is *0*\**i*, where the (zero) imaginary part of the result has the same sign as *b*. Otherwise, the result is *z*.

These functions do not signal any floating point exceptions.

## STANDARDS

The **cimag**(), **conj**(), **cproj**(), and **creal**() functions conform to ISO/IEC 9899:1999 (“ISO C99”).

## HISTORY

The **cimag**(), **conj**() and **creal**() functions first appeared in FreeBSD 5.3. The **cproj**() functions appeared in FreeBSD 8.0.