C Pocket Reference

Mathematical Functions for Complex Floating Types

Functions and macros for complex numbers are declared in the header file complex.h (*). The functions shown in Table 1-34 have one parameter and return a value of type double complex.

Table 1-34. Mathematical functions for the type double complex

Mathematical function	C function
Trigonometric functions: Sine, cosine, tangent Arcsine, arccosine Arctangent	csin(), ccos(), ctan() casin(), cacos() catan()
Hyperbolic functions	csinh(), ccosh(), ctanh(), casinh(), cacosh(), catanh()
Powers, square root	cpow(), csqrt()
Exponential function	cexp()
Logarithm	clog()
Complex conjugate	conj()

The functions shown in Table 1-35 have one parameter of type double complex and return a value of type double.

Table 1-35. Complex functions with type double

Mathematical function	C function
Absolute value	cabs()
Argument (phase angle)	carg()
Real and imaginary parts	creal(), cimag()
Projection onto the Riemann sphere	cproj()

These functions also have versions for float complex and long double complex, with names ending in f and l.

Table 1-36 shows macros that are defined for complex types.

Table 1-36. Macros for complex types

Macro	Replacement value
complex	_Complex
_Complex_I	The imaginary unit, i. e., the number i such that i 2 = -1, with type const float _Complex
imaginary	_Imaginary
_Imaginary_I	The imaginary unit, with type const float _Imaginary
I	_Imaginary_I if the compiler supports ...