xref: /titanic_52/usr/src/lib/libm/common/complex/ctan.c (revision ddc0e0b53c661f6e439e3b7072b3ef353eadb4af)
125c28e83SPiotr Jasiukajtis /*
225c28e83SPiotr Jasiukajtis  * CDDL HEADER START
325c28e83SPiotr Jasiukajtis  *
425c28e83SPiotr Jasiukajtis  * The contents of this file are subject to the terms of the
525c28e83SPiotr Jasiukajtis  * Common Development and Distribution License (the "License").
625c28e83SPiotr Jasiukajtis  * You may not use this file except in compliance with the License.
725c28e83SPiotr Jasiukajtis  *
825c28e83SPiotr Jasiukajtis  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
925c28e83SPiotr Jasiukajtis  * or http://www.opensolaris.org/os/licensing.
1025c28e83SPiotr Jasiukajtis  * See the License for the specific language governing permissions
1125c28e83SPiotr Jasiukajtis  * and limitations under the License.
1225c28e83SPiotr Jasiukajtis  *
1325c28e83SPiotr Jasiukajtis  * When distributing Covered Code, include this CDDL HEADER in each
1425c28e83SPiotr Jasiukajtis  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
1525c28e83SPiotr Jasiukajtis  * If applicable, add the following below this CDDL HEADER, with the
1625c28e83SPiotr Jasiukajtis  * fields enclosed by brackets "[]" replaced with your own identifying
1725c28e83SPiotr Jasiukajtis  * information: Portions Copyright [yyyy] [name of copyright owner]
1825c28e83SPiotr Jasiukajtis  *
1925c28e83SPiotr Jasiukajtis  * CDDL HEADER END
2025c28e83SPiotr Jasiukajtis  */
2125c28e83SPiotr Jasiukajtis 
2225c28e83SPiotr Jasiukajtis /*
2325c28e83SPiotr Jasiukajtis  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
2425c28e83SPiotr Jasiukajtis  */
2525c28e83SPiotr Jasiukajtis /*
2625c28e83SPiotr Jasiukajtis  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
2725c28e83SPiotr Jasiukajtis  * Use is subject to license terms.
2825c28e83SPiotr Jasiukajtis  */
2925c28e83SPiotr Jasiukajtis 
30*ddc0e0b5SRichard Lowe #pragma weak __ctan = ctan
3125c28e83SPiotr Jasiukajtis 
3225c28e83SPiotr Jasiukajtis /* INDENT OFF */
3325c28e83SPiotr Jasiukajtis /*
3425c28e83SPiotr Jasiukajtis  * dcomplex ctan(dcomplex z);
3525c28e83SPiotr Jasiukajtis  *
3625c28e83SPiotr Jasiukajtis  * If z = x+iy, then since ctan(iz) = i*ctanh(z),  we have
3725c28e83SPiotr Jasiukajtis  *
3825c28e83SPiotr Jasiukajtis  * ctan(z)	= ctan((-1)*(-z)) = ctan(i*i*(-z))
3925c28e83SPiotr Jasiukajtis  *		= i*ctanh(i*(-z)) = i*ctanh(i*(-x-yi))
4025c28e83SPiotr Jasiukajtis  *		= i*ctanh(y-ix)
4125c28e83SPiotr Jasiukajtis  *		= -Im(ctanh(y-ix))+i*Re(ctanh(y-ix))
4225c28e83SPiotr Jasiukajtis  */
4325c28e83SPiotr Jasiukajtis /* INDENT ON */
4425c28e83SPiotr Jasiukajtis 
4525c28e83SPiotr Jasiukajtis #include "libm.h"
4625c28e83SPiotr Jasiukajtis #include "complex_wrapper.h"
4725c28e83SPiotr Jasiukajtis 
4825c28e83SPiotr Jasiukajtis dcomplex
4925c28e83SPiotr Jasiukajtis ctan(dcomplex z) {
5025c28e83SPiotr Jasiukajtis 	double x, y;
5125c28e83SPiotr Jasiukajtis 	dcomplex ans, ct;
5225c28e83SPiotr Jasiukajtis 
5325c28e83SPiotr Jasiukajtis 	x = D_RE(z);
5425c28e83SPiotr Jasiukajtis 	y = D_IM(z);
5525c28e83SPiotr Jasiukajtis 	D_RE(z) = y;
5625c28e83SPiotr Jasiukajtis 	D_IM(z) = -x;
5725c28e83SPiotr Jasiukajtis 	ct = ctanh(z);
5825c28e83SPiotr Jasiukajtis 	D_RE(ans) = -D_IM(ct);
5925c28e83SPiotr Jasiukajtis 	D_IM(ans) = D_RE(ct);
6025c28e83SPiotr Jasiukajtis 	return (ans);
6125c28e83SPiotr Jasiukajtis }
62