main.c

/**
* @license Apache-2.0
*
* Copyright (c) 2021 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

#include "stdlib/math/base/special/cflipsign.h"
#include "stdlib/math/base/assert/is_negative_zero.h"
#include <complex.h>

/**
* Returns a double-precision complex floating-point number with the same magnitude as `z` and the sign of `y*z`.
*
* @param z       input value
* @param y       number from which to derive the sign
* @return        result
*
* @example
* double complex y = stdlib_base_cflipsign( 3.5-2.5*I, -1.0 );
* // returns -3.5+2.5*I
*/
double complex stdlib_base_cflipsign( const double complex z, const double y ) {
	double re = creal( z );
	double im = cimag( z );
	if ( y < 0 || stdlib_base_is_negative_zero( y ) ) {
		re = -re;
		im = -im;
	}
	return re + im*I;
}