cpowf, cpow, cpowl

 

C

Language

Headers

Type support

Program utilities

Variadic function support

Error handling

Dynamic memory management

Strings library

Algorithms

Numerics

Date and time utilities

Input/output support

Localization support

Concurrency support (哋它亢11)

Technical Specifications

Symbol index

 

Numerics

Common mathematical functions

Floating-point environment (哋它亢99)

Pseudo-random number generation

Complex number arithmetic (哋它亢99)

Type-generic math (哋它亢99)

 

Complex number arithmetic

Types and the imaginary constant
complex (哋它亢99) _Complex_I (哋它亢99)     CMPLX (哋它亢11)	imaginary (哋它亢99) _Imaginary_I (哋它亢99) I (哋它亢99)
Manipulation
cimag (哋它亢99) creal (哋它亢99) carg (哋它亢99)	cabs (哋它亢99) conj (哋它亢99) cproj (哋它亢99)
Power and exponential functions
cexp (哋它亢99) clog (哋它亢99)	cpow (哋它亢99) csqrt (哋它亢99)
Trigonometric functions
ccos (哋它亢99) csin (哋它亢99) ctan (哋它亢99)	cacos (哋它亢99) casin (哋它亢99) catan (哋它亢99)
Hyperbolic functions
ccosh (哋它亢99) csinh (哋它亢99) ctanh (哋它亢99)	cacosh (哋它亢99) casinh (哋它亢99) catanh (哋它亢99)

 

Defined in header <complex.h>
float complex       cpowf( float complex x, float complex y );	(1)	(since 哋它亢99)
double complex      cpow( double complex x, double complex y );	(2)	(since 哋它亢99)
long double complex cpowl( long double complex x, long double complex y );	(3)	(since 哋它亢99)
Defined in header <tgmath.h>
#define pow( x, y )	(4)	(since 哋它亢99)

1-3) Computes the complex power function xy
, with branch cut for the first parameter along the negative real axis.

4) Type-generic macro: If any argument has type long double complex, cpowl is called. if any argument has type double complex, cpow is called, if any argument has type float complex, cpowf is called. If the arguments are real or integer, then the macro invokes the corresponding real function (powf, pow, powl). If any argument is imaginary, the corresponding complex number version is called.

Parameters

x, y

-

complex argument

Return value

If no errors occur, the complex power xy
, is returned.

Errors and special cases are handled as if the operation is implemented by cexp(y*clog(x)), except that the implementation is allowed to treat special cases more carefully.

Example

Run this code

#include <stdio.h>
#include <complex.h>
 
int main(void)
{    
    double complex z = cpow(1.0+2.0*I, 2);
    printf("(1+2i)^2 = %.1f%+.1fi\n", creal(z), cimag(z));
 
    double complex z2 = cpow(-1, 0.5);
    printf("(-1+0i)^0.5 = %.1f%+.1fi\n", creal(z2), cimag(z2));
 
    double complex z3 = cpow(conj(-1), 0.5); // other side of the cut
    printf("(-1-0i)^0.5 = %.1f%+.1fi\n", creal(z3), cimag(z3));
 
    double complex z4 = cpow(I, I); // i^i = exp(-pi/2)
    printf("i^i = %f%+fi\n", creal(z4), cimag(z4));
}

Output:

(1+2i)^2 = -3.0+4.0i
(-1+0i)^0.5 = 0.0+1.0i
(-1-0i)^0.5 = 0.0-1.0i
i^i = 0.207880+0.000000i

References

• 哋它亢11 standard (ISO/IEC 9899:2011):

• 7.3.8.2 The cpow functions (p: 195-196)

• 7.25 Type-generic math <tgmath.h> (p: 373-375)

• G.6.4.1 The cpow functions (p: 544)

• G.7 Type-generic math <tgmath.h> (p: 545)

• 哋它亢99 standard (ISO/IEC 9899:1999):

• 7.3.8.2 The cpow functions (p: 177)

• 7.22 Type-generic math <tgmath.h> (p: 335-337)

• G.6.4.1 The cpow functions (p: 479)

• G.7 Type-generic math <tgmath.h> (p: 480)

See also

csqrtcsqrtfcsqrtl (哋它亢99)(哋它亢99)(哋它亢99)	computes the complex square root (function)
powpowfpowl (哋它亢99)(哋它亢99)	computes a number raised to the given power (\(\small{x^y}\)xy) (function)