cpowf, cpow, cpowl
From cppreference.com
C
Concurrency support (C11)
Complex number arithmetic
Types and the imaginary constant
Manipulation
Power and exponential functions
Trigonometric functions
Hyperbolic functions
Defined in header
<complex.h>
Defined in header
<tgmath.h>
#define pow( x, y )
(4)
(since C99)
1-3) Computes the complex power function xy
, with branch cut for the first parameter along the negative real axis.
, 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.[edit] Parameters
x, y
-
complex argument
[edit] 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.
[edit] 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
[edit] References
- C11 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)
- C99 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)
[edit] See also
C++ documentation for pow