Stan Math Library  2.9.0
reverse mode automatic differentiation
asinh.hpp
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1 #ifndef STAN_MATH_REV_SCAL_FUN_ASINH_HPP
2 #define STAN_MATH_REV_SCAL_FUN_ASINH_HPP
3 
4 #include <math.h>
5 #include <stan/math/rev/core.hpp>
6 #include <boost/math/special_functions/fpclassify.hpp>
7 #include <cmath>
8 #include <valarray>
9 
10 #ifdef _MSC_VER
11 #include <boost/math/special_functions/asinh.hpp>
12 using boost::math::asinh;
13 #endif
14 
15 namespace stan {
16  namespace math {
17 
18  namespace {
19  class asinh_vari : public op_v_vari {
20  public:
21  asinh_vari(double val, vari* avi) :
22  op_v_vari(val, avi) {
23  }
24  void chain() {
25  avi_->adj_ += adj_ / std::sqrt(avi_->val_ * avi_->val_ + 1.0);
26  }
27  };
28  }
29 
67  inline var asinh(const var& a) {
68  if (boost::math::isinf(a.val()))
69  return var(new asinh_vari(a.val(), a.vi_));
70  return var(new asinh_vari(::asinh(a.val()), a.vi_));
71  }
72 
73  }
74 }
75 #endif
fvar< T > sqrt(const fvar< T > &x)
Definition: sqrt.hpp:15
Independent (input) and dependent (output) variables for gradients.
Definition: var.hpp:31
bool isinf(const stan::math::var &v)
Checks if the given number is infinite.
Definition: boost_isinf.hpp:22
fvar< T > asinh(const fvar< T > &x)
Definition: asinh.hpp:13
vari * vi_
Pointer to the implementation of this variable.
Definition: var.hpp:43
var asinh(const var &a)
The inverse hyperbolic sine function for variables (C99).
Definition: asinh.hpp:67
double val() const
Return the value of this variable.
Definition: var.hpp:233

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