cacos

Compute the arccosine of a complex number.

Interface Definition

C interface:

float complex cacosf(float complex x);

double complex cacos(double complex x);

Parameters

Parameter	Type	Description	Input/Output
x	For cacosf, x is of complex single-precision floating-point type. For cacos, x is of complex double-precision floating-point type.	Floating-point value of the input data.	Input

Return Value

Normal range: The arccosine of the complex number x is returned.

Special values: See the following table.

Real Part of the Input (x.real)	Imaginary Part of the Input (x.imag)	Real Part of the Output (y.real)	Imaginary Part of the Output (y.imag)
0	0	π/2	0
0	0	π/2	0
0	inf	π/2	-inf
0	-inf	π/2	inf
0	SNaN	π/2	NaN
0	–SNaN	π/2	NaN
0	QNaN	π/2	NaN
0	–QNaN	π/2	NaN
0	0	π/2	0
0	0	π/2	0
0	inf	π/2	-inf
0	-inf	π/2	inf
0	SNaN	π/2	NaN
0	–SNaN	π/2	NaN
0	QNaN	π/2	NaN
0	–QNaN	π/2	NaN
inf	0	0	-inf
inf	0	0	inf
inf	inf	π/4	-inf
inf	-inf	π/4	inf
inf	SNaN	NaN	-inf
inf	–SNaN	NaN	-inf
inf	QNaN	NaN	-inf
inf	–QNaN	NaN	-inf
-inf	0	pi	-inf
-inf	0	pi	inf
-inf	inf	3*π/4	-inf
-inf	-inf	3*π/4	inf
-inf	SNaN	NaN	-inf
-inf	–SNaN	NaN	-inf
-inf	QNaN	NaN	-inf
-inf	–QNaN	NaN	-inf
SNaN	0	NaN	NaN
SNaN	0	NaN	NaN
SNaN	inf	NaN	-inf
SNaN	-inf	NaN	inf
SNaN	SNaN	NaN	NaN
SNaN	–SNaN	NaN	NaN
SNaN	QNaN	NaN	NaN
SNaN	–QNaN	NaN	NaN
–SNaN	0	NaN	NaN
–SNaN	0	NaN	NaN
–SNaN	inf	NaN	-inf
–SNaN	-inf	NaN	inf
–SNaN	SNaN	NaN	NaN
–SNaN	–SNaN	NaN	NaN
–SNaN	QNaN	NaN	NaN
–SNaN	–QNaN	NaN	NaN
QNaN	0	NaN	NaN
QNaN	0	NaN	NaN
QNaN	inf	NaN	-inf
QNaN	-inf	NaN	inf
QNaN	SNaN	NaN	NaN
QNaN	–SNaN	NaN	NaN
QNaN	QNaN	NaN	NaN
QNaN	–QNaN	NaN	NaN
–QNaN	0	NaN	NaN
–QNaN	0	NaN	NaN
–QNaN	inf	NaN	-inf
–QNaN	-inf	NaN	inf
–QNaN	SNaN	NaN	NaN
–QNaN	–SNaN	NaN	NaN
–QNaN	QNaN	NaN	NaN
–QNaN	–QNaN	NaN	NaN

Dependency

C: "kc.h"

Example

C interface:

// typical usage
double x1 = INFINITY, y1 = INFINITY;
double x2 = 2.0, y2 = 3.0;
double x3 = -2.5, y3 = -3.4;
double x4 = NAN, y4 = NAN;
double x5 = 0, y5 = 0;
// print result
printf("/*\n");
printf(" * cacos(%.2f + %.2f*I) = %.6f\n", x1, y1, cacos(__builtin_complex(x1, y1)));
printf(" * cacos(%.2f + %.2f*I) = %.6f\n", x2, y2, cacos(__builtin_complex(x2, y2)));
printf(" * cacos(%.2f + %.2f*I) = %.6f\n", x3, y3, cacos(__builtin_complex(x3, y3)));
printf(" * cacos(%.2f + %.2f*I) = %.6f\n", x4, y4, cacos(__builtin_complex(x4, y4)));
printf(" * cacos(%.2f + %.2f*I) = %.6f\n", x5, y5, cacos(__builtin_complex(x5, y5)));
printf(" **/\n");
/*
 * cacos(inf + inf*I) = 0.785398
 * cacos(2.00 + 3.00*I) = 1.000144
 * cacos(-2.50 + -3.40*I) = 2.191594
 * cacos(nan + nan*I) = nan
 * cacos(0.00 + 0.00*I) = 1.570796
 **/

Parent topic: Function Syntax