Stan Math Library  2.15.0
reverse mode automatic differentiation
acosh.hpp
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1 #ifndef STAN_MATH_REV_SCAL_FUN_ACOSH_HPP
2 #define STAN_MATH_REV_SCAL_FUN_ACOSH_HPP
3 
5 #include <stan/math/rev/core.hpp>
6 #include <cmath>
7 
8 namespace stan {
9  namespace math {
10 
11  namespace {
12  class acosh_vari : public op_v_vari {
13  public:
14  acosh_vari(double val, vari* avi) :
15  op_v_vari(val, avi) {
16  }
17  void chain() {
18  avi_->adj_ += adj_ / std::sqrt(avi_->val_ * avi_->val_ - 1.0);
19  }
20  };
21  }
22 
62  inline var acosh(const var& a) {
63  return var(new acosh_vari(stan::math::acosh(a.val()), a.vi_));
64  }
65 
66  }
67 }
68 #endif
fvar< T > sqrt(const fvar< T > &x)
Definition: sqrt.hpp:14
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
fvar< T > acosh(const fvar< T > &x)
Definition: acosh.hpp:12
double val() const
Return the value of this variable.
Definition: var.hpp:230

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