Stan Math Library  2.12.0
reverse mode automatic differentiation
multiply_log.hpp
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1 #ifndef STAN_MATH_FWD_SCAL_FUN_MULTIPLY_LOG_HPP
2 #define STAN_MATH_FWD_SCAL_FUN_MULTIPLY_LOG_HPP
3 
4 #include <stan/math/fwd/core.hpp>
5 
7 
8 namespace stan {
9  namespace math {
10 
11  template <typename T>
12  inline
13  fvar<T>
14  multiply_log(const fvar<T>& x1, const fvar<T>& x2) {
15  using std::log;
16  return fvar<T>(multiply_log(x1.val_, x2.val_),
17  x1.d_ * log(x2.val_) + x1.val_ * x2.d_ / x2.val_);
18  }
19 
20  template <typename T>
21  inline
22  fvar<T>
23  multiply_log(const double x1, const fvar<T>& x2) {
24  using std::log;
25  return fvar<T>(multiply_log(x1, x2.val_),
26  x1 * x2.d_ / x2.val_);
27  }
28 
29  template <typename T>
30  inline
31  fvar<T>
32  multiply_log(const fvar<T>& x1, const double x2) {
33  using std::log;
34  return fvar<T>(multiply_log(x1.val_, x2),
35  x1.d_ * log(x2));
36  }
37  }
38 }
39 #endif
fvar< T > log(const fvar< T > &x)
Definition: log.hpp:14
fvar< T > multiply_log(const fvar< T > &x1, const fvar< T > &x2)

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