clog10

Compute the base-10 logarithm of a complex number.

Interface Definition

C interface:

float complex clog10f(float complex x);

double complex clog10(double complex x);

long double complex clog10l(long double complex x);

Parameters

Parameter	Type	Description	Input/Output
x	For clog10f, x is of complex single-precision floating-point type. For clog10, x is of complex double-precision floating-point type. For clog10l, x is of complex, long, double-precision floating-point type.	Floating-point value of the input data.	Input

Parameter

Type

Description

Input/Output

For clog10f, x is of complex single-precision floating-point type.

For clog10, x is of complex double-precision floating-point type.

For clog10l, x is of complex, long, double-precision floating-point type.

Floating-point value of the input data.

Input

Return Value

The base-10 logarithm y of x is returned.

The special values are listed in 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	-inf	+0
+0	-0	-inf	-0
+0	inf	inf	0x3fe5d47c4cb2fba1(pi/2ln10)
+0	-inf	inf	0xbfe5d47c4cb2fba1(-pi/2ln10)
+0	SNaN	NaN	NaN
+0	–SNaN	NaN	NaN
+0	QNaN	NaN	NaN
+0	–QNaN	NaN	NaN
-0	+0	-inf	0x3ff5d47c4cb2fba1(pi/ln10)
-0	-0	-inf	0xbff5d47c4cb2fba1(-pi/ln10)
-0	inf	inf	0x3fe5d47c4cb2fba1(pi/2ln10)
-0	-inf	inf	0xbfe5d47c4cb2fba1(-pi/2ln10)
-0	SNaN	NaN	NaN
-0	–SNaN	NaN	NaN
-0	QNaN	NaN	NaN
-0	–QNaN	NaN	NaN
inf	+0	inf	+0
inf	-0	inf	-0
inf	inf	inf	0x3fd5d47c4cb2fba1(pi/4ln10)
inf	-inf	inf	0xbfd5d47c4cb2fba1(-pi/4ln10)
inf	SNaN	inf	NaN
inf	–SNaN	inf	NaN
inf	QNaN	inf	NaN
inf	–QNaN	inf	NaN
-inf	+0	inf	0x3ff5d47c4cb2fba1(pi/ln10)
-inf	-0	inf	0xbff5d47c4cb2fba1(-pi/ln10)
-inf	inf	inf	0x3ff05f5d39863cb9(3*pi/4ln10)
-inf	-inf	inf	0xbff05f5d39863cb9(-3*pi/4ln10)
-inf	SNaN	inf	NaN
-inf	–SNaN	inf	NaN
-inf	QNaN	inf	NaN
-inf	–QNaN	inf	NaN
SNaN	+0	NaN	NaN
SNaN	-0	NaN	NaN
SNaN	inf	inf	NaN
SNaN	-inf	inf	NaN
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	inf	NaN
–SNaN	-inf	inf	NaN
–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	inf	NaN
QNaN	-inf	inf	NaN
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	inf	NaN
–QNaN	-inf	inf	NaN
–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;
    double complex z1 = clog10(__builtin_complex(x1, y1));
    double complex z2 = clog10(__builtin_complex(x2, y2));
    double complex z3 = clog10(__builtin_complex(x3, y3));
    double complex z4 = clog10(__builtin_complex(x4, y4));
    double complex z5 = clog10(__builtin_complex(x5, y5));
    // print result
    printf("/*\n");
    printf(" * clog10(%.2f + %.2f*I) = %.6f + %.6f*I\n", x1, y1, __real__(z1), __imag__(z1));
    printf(" * clog10(%.2f + %.2f*I) = %.6f + %.6f*I\n", x2, y2, __real__(z2), __imag__(z2));
    printf(" * clog10(%.2f + %.2f*I) = %.6f + %.6f*I\n", x3, y3, __real__(z3), __imag__(z3));
    printf(" * clog10(%.2f + %.2f*I) = %.6f + %.6f*I\n", x4, y4, __real__(z4), __imag__(z4));
    printf(" * clog10(%.2f + %.2f*I) = %.6f + %.6f*I\n", x5, y5, __real__(z5), __imag__(z5));
    printf(" **/\n");
    /*
     * clog10(inf + inf*I) = inf + 0.341094*I
     * clog10(2.00 + 3.00*I) = 0.556972 + 0.426822*I
     * clog10(-2.50 + -3.40*I) = 0.625332 + -0.957541*I
     * clog10(nan + nan*I) = nan + nan*I
     * clog10(0.00 + 0.00*I) = -inf + 0.000000*I
     **/

Parent topic: Function Syntax