Stan Math Library  2.15.0
reverse mode automatic differentiation
log2.hpp
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1 #ifndef STAN_MATH_FWD_SCAL_FUN_LOG2_HPP
2 #define STAN_MATH_FWD_SCAL_FUN_LOG2_HPP
3 
4 #include <stan/math/fwd/core.hpp>
7 
8 namespace stan {
9  namespace math {
10 
18  template <typename T>
19  inline fvar<T> log2(const fvar<T>& x) {
20  if (x.val_ < 0.0)
22  else
23  return fvar<T>(log2(x.val_), x.d_ / (x.val_ * LOG_2));
24  }
25 
26  }
27 }
28 #endif
const double LOG_2
The natural logarithm of 2, .
Definition: constants.hpp:32
const double NOT_A_NUMBER
(Quiet) not-a-number value.
Definition: constants.hpp:55
fvar< T > log2(const fvar< T > &x)
Return the base two logarithm of the specified argument.
Definition: log2.hpp:19

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