1 // Copyright (c) 1998-1999 Matra Datavision
2 // Copyright (c) 1999-2014 OPEN CASCADE SAS
3 //
4 // This file is part of Open CASCADE Technology software library.
5 //
6 // This library is free software; you can redistribute it and/or modify it under
7 // the terms of the GNU Lesser General Public License version 2.1 as published
8 // by the Free Software Foundation, with special exception defined in the file
9 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
10 // distribution for complete text of the license and disclaimer of any warranty.
11 //
12 // Alternatively, this file may be used under the terms of Open CASCADE
13 // commercial license or contractual agreement.
14 
15 #include <Standard_math.hxx>
16 
17 // MSVC versions prior to 12 did not provided acosh, asinh, atanh functions in standard library
18 #if defined(_MSC_VER) && (_MSC_VER < 1800)
19 
acosh(double X)20 Standard_EXPORT double  __cdecl acosh( double X)
21 {
22 	double  res;
23 	res = log(X + sqrt(X * X - 1));
24 	return res;
25 };
asinh(double X)26 Standard_EXPORT double  __cdecl  asinh( double X)
27 {
28 	double  res;
29 //  Modified by Sergey KHROMOV - Mon Nov 11 16:27:11 2002 Begin
30 //  Correction of the formula to avoid numerical problems.
31 //	res = log(X + sqrt(X * X + 1));
32 	if (X > 0.)
33 	res = log(X + sqrt(X * X + 1));
34 	else
35 	  res = -log(sqrt(X * X + 1) - X);
36 //  Modified by Sergey KHROMOV - Mon Nov 11 16:27:13 2002 End
37 	return res;
38 };
atanh(double X)39 Standard_EXPORT double __cdecl  atanh( double X)
40 {
41 	double res;
42 	res = log((1 + X) / (1 - X)) / 2;
43 	return res;
44 };
45 
46 #endif
47