Stan Math Library  2.14.0
reverse mode automatic differentiation
atanh.hpp
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1 #ifndef STAN_MATH_REV_SCAL_FUN_ATANH_HPP
2 #define STAN_MATH_REV_SCAL_FUN_ATANH_HPP
3 
5 #include <stan/math/rev/core.hpp>
6 #include <limits>
7 
8 namespace stan {
9  namespace math {
10 
11  namespace {
12  class atanh_vari : public op_v_vari {
13  public:
14  atanh_vari(double val, vari* avi) :
15  op_v_vari(val, avi) {
16  }
17  void chain() {
18  avi_->adj_ += adj_ / (1.0 - avi_->val_ * avi_->val_);
19  }
20  };
21  }
22 
62  inline var atanh(const var& a) {
63  return var(new atanh_vari(atanh(a.val()), a.vi_));
64  }
65 
66  }
67 }
68 #endif
fvar< T > atanh(const fvar< T > &x)
Return inverse hyperbolic tangent of specified value.
Definition: atanh.hpp:21
Independent (input) and dependent (output) variables for gradients.
Definition: var.hpp:30
vari * vi_
Pointer to the implementation of this variable.
Definition: var.hpp:42
double val() const
Return the value of this variable.
Definition: var.hpp:230

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