Stan Math Library  2.10.0
reverse mode automatic differentiation
trunc.hpp
Go to the documentation of this file.
1 #ifndef STAN_MATH_REV_SCAL_FUN_TRUNC_HPP
2 #define STAN_MATH_REV_SCAL_FUN_TRUNC_HPP
3 
4 #include <math.h>
5 #include <stan/math/rev/core.hpp>
6 #include <boost/math/special_functions/fpclassify.hpp>
7 #include <limits>
8 
9 #ifdef _MSC_VER
10 #include <boost/math/special_functions/trunc.hpp>
11 using boost::math::trunc;
12 #endif
13 
14 namespace stan {
15  namespace math {
16 
17  namespace {
18  class trunc_vari : public op_v_vari {
19  public:
20  explicit trunc_vari(vari* avi) :
21  op_v_vari(::trunc(avi->val_), avi) {
22  }
23  void chain() {
24  if (unlikely(boost::math::isnan(avi_->val_)))
25  avi_->adj_ = std::numeric_limits<double>::quiet_NaN();
26  }
27  };
28  }
29 
60  inline var trunc(const var& a) {
61  return var(new trunc_vari(a.vi_));
62  }
63 
64  }
65 }
66 #endif
var trunc(const var &a)
Returns the truncatation of the specified variable (C99).
Definition: trunc.hpp:60
Independent (input) and dependent (output) variables for gradients.
Definition: var.hpp:31
fvar< T > trunc(const fvar< T > &x)
Definition: trunc.hpp:12
bool isnan(const stan::math::var &v)
Checks if the given number is NaN.
Definition: boost_isnan.hpp:22
#define unlikely(x)
Definition: likely.hpp:9
vari * vi_
Pointer to the implementation of this variable.
Definition: var.hpp:43

     [ Stan Home Page ] © 2011–2016, Stan Development Team.