Stan Math Library  2.15.0
reverse mode automatic differentiation
log.hpp
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1 #ifndef STAN_MATH_FWD_SCAL_FUN_LOG_HPP
2 #define STAN_MATH_FWD_SCAL_FUN_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  log(const fvar<T>& x) {
15  using std::log;
16  if (x.val_ < 0.0)
18  else
19  return fvar<T>(log(x.val_), x.d_ / x.val_);
20  }
21  }
22 }
23 #endif
const double NOT_A_NUMBER
(Quiet) not-a-number value.
Definition: constants.hpp:55
fvar< T > log(const fvar< T > &x)
Definition: log.hpp:14
var log(const var &a)
Return the natural log of the specified variable (cmath).
Definition: log.hpp:50

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