ctan.c revision 25c28e83beb90e7c80452a7c818c5e6f73a07dc8
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * CDDL HEADER START
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * The contents of this file are subject to the terms of the
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Common Development and Distribution License (the "License").
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * You may not use this file except in compliance with the License.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * or http://www.opensolaris.org/os/licensing.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * See the License for the specific language governing permissions
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * and limitations under the License.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
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25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * fields enclosed by brackets "[]" replaced with your own identifying
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * information: Portions Copyright [yyyy] [name of copyright owner]
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25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * CDDL HEADER END
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Use is subject to license terms.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#pragma weak ctan = __ctan
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/* INDENT OFF */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * dcomplex ctan(dcomplex z);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * If z = x+iy, then since ctan(iz) = i*ctanh(z), we have
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * ctan(z) = ctan((-1)*(-z)) = ctan(i*i*(-z))
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * = i*ctanh(i*(-z)) = i*ctanh(i*(-x-yi))
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * = i*ctanh(y-ix)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * = -Im(ctanh(y-ix))+i*Re(ctanh(y-ix))
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/* INDENT ON */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "libm.h"
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "complex_wrapper.h"
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisdcomplex
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisctan(dcomplex z) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis double x, y;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis dcomplex ans, ct;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis x = D_RE(z);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis y = D_IM(z);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis D_RE(z) = y;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis D_IM(z) = -x;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis ct = ctanh(z);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis D_RE(ans) = -D_IM(ct);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis D_IM(ans) = D_RE(ct);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (ans);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis}