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copysign

From cppreference.com
< c‎ | numeric‎ | math
 
 
 
Common mathematical functions
Functions
Basic operations
(C99)
(C99)
(C99)
(C99)
(C99)
(C99)(C99)(C99)
Exponential functions
(C99)
(C99)
(C99)
(C99)
Power functions
(C99)
(C99)
Trigonometric and hyperbolic functions
(C99)
(C99)
(C99)
Error and gamma functions
(C99)
(C99)
(C99)
(C99)
Nearest integer floating point operations
(C99)(C99)(C99)
(C99)
(C99)(C99)(C99)
Floating point manipulation functions
(C99)(C99)
(C99)
(C99)
copysign
(C99)
Classification
(C99)
(C99)
(C99)
Macro constants
 
Defined in header <math.h>
float       copysignf( float x, float y );
(since C99)
double      copysign( double x, double y );
(since C99)
long double copysignl( long double x, long double y );
(since C99)

Composes a floating point value with the magnitude of x and the sign of y.

Contents

[edit] Parameters

x, y - floating point values

[edit] Return value

Floating point value with the magnitude of x and the sign of y

[edit] Example

#include <stdio.h>
#include <math.h>
 
int main()
{
    printf("copysign(1.0,+2.0)      = %+.1f\n", copysign(1.0,+2.0));
    printf("copysign(1.0,-2.0)      = %+.1f\n", copysign(1.0,-2.0));
    printf("copysign(INFINITY,-2.0) = %f\n",    copysign(INFINITY,-2.0));
    printf("copysign(NAN,-2.0)      = %f\n",    copysign(NAN,-2.0));
 
    return 0;
}

Possible output:

copysign(1.0,+2.0)      = +1.0
copysign(1.0,-2.0)      = -1.0
copysign(INFINITY,-2.0) = -inf
copysign(NAN,-2.0)      = -nan

[edit] See also

absolute value of a floating point value (|x|)
(function) [edit]
checks if the given number is negative
(function) [edit]
C++ documentation for copysign