Stan Math Library  2.11.0
reverse mode automatic differentiation
log1m.hpp
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1 #ifndef STAN_MATH_REV_SCAL_FUN_LOG1M_HPP
2 #define STAN_MATH_REV_SCAL_FUN_LOG1M_HPP
3 
4 #include <stan/math/rev/core.hpp>
6 
7 namespace stan {
8  namespace math {
9 
10  namespace {
11  class log1m_vari : public op_v_vari {
12  public:
13  explicit log1m_vari(vari* avi) :
14  op_v_vari(stan::math::log1p(-avi->val_), avi) {
15  }
16  void chain() {
17  avi_->adj_ += adj_ / (avi_->val_ - 1);
18  }
19  };
20  }
21 
32  inline var log1m(const stan::math::var& a) {
33  return var(new log1m_vari(a.vi_));
34  }
35 
36  }
37 }
38 #endif
Independent (input) and dependent (output) variables for gradients.
Definition: var.hpp:31
vari * vi_
Pointer to the implementation of this variable.
Definition: var.hpp:43
fvar< T > log1p(const fvar< T > &x)
Definition: log1p.hpp:16
fvar< T > log1m(const fvar< T > &x)
Definition: log1m.hpp:16

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