text: /*-
   * Copyright (c) 2014-2018 Carsten Sonne Larsen <cs@innolan.net>
   * Copyright (c) 2007 The NetBSD Foundation, Inc.
   * All rights reserved.
   *
   * This code is derived from software written by Stephen L. Moshier.
   * It is redistributed by the NetBSD Foundation by permission of the author.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * The original source code can be obtained from:
   * http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libm/complex/csin.c?rev=1.1
   *
   * Project homepage:
   * https://amath.innolan.net
   * 
   */
  
  #include "prim.h"
  
  /**
   * @brief  Sine of a complex number
   * @details
   * Calculated according to description at wikipedia:<BR>
   * https://wikipedia.org/wiki/Sine#Sine_with_a_complex_argument
   * <pre>
   * a+bi
   * real = sin(a) * cosh(b)
   * imag = cos(a) * sinh(b)
   * </pre>
   */
  complex csin(complex z)
  {
      complex w;
      double a, b;
      double ch, sh;
  
      a = creal(z);
      b = cimag(z);
      cchsh(b, &ch, &sh);
      w = cpack((sin(a) * ch), (cos(a) * sh));
  
      return w;
  }
  