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IMP Reference Guide  2.13.0
The Integrative Modeling Platform
algebra/constants.h
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1 /**
2  * \file IMP/algebra/constants.h \brief Various useful constants.
3  *
4  * Copyright 2007-2020 IMP Inventors. All rights reserved.
5  *
6  */
7 
8 #ifndef IMPALGEBRA_CONSTANTS_H
9 #define IMPALGEBRA_CONSTANTS_H
10 
11 #include <IMP/algebra/algebra_config.h>
12 #include <cmath>
13 
14 IMPALGEBRA_BEGIN_NAMESPACE
15 
16 #if defined(_GLIBCXX_USE_C99_MATH) && defined(__GNUC__)
17 //! the constant pi
18 static const double PI = M_PI;
19 #else
20 //! the constant pi
21 static const double PI = 3.1415926535897931;
22 #endif // C99
23 
24 IMPALGEBRA_END_NAMESPACE
25 
26 #endif /* IMPALGEBRA_CONSTANTS_H */
static const double PI
the constant pi