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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>
5 #include <stan/math/prim/scal/fun/constants.hpp>
6 #include <stan/math/prim/scal/fun/log2.hpp>
7
8 namespace stan {
9 namespace math {
10
11 template <typename T>
12 inline
13 fvar<T>
14 log2(const fvar<T>& x) {
15 using std::log;
16 if (x.val_ < 0.0)
17 return fvar<T>(NOT_A_NUMBER, NOT_A_NUMBER);
18 else
19 return fvar<T>(log2(x.val_), x.d_ / (x.val_ * LOG_2));
20 }
21
22 }
23 }
24 #endif
stan::math::LOG_2
const double LOG_2
The natural logarithm of 2, .
Definition: constants.hpp:32
core.hpp
stan::math::fvar::d_
T d_
Definition: fvar.hpp:14
stan::math::NOT_A_NUMBER
const double NOT_A_NUMBER
(Quiet) not-a-number value.
Definition: constants.hpp:55
stan
Definition: log_sum_exp.hpp:8
stan::math::log
fvar< T > log(const fvar< T > &x)
Definition: log.hpp:14
stan::math::fvar::val_
T val_
Definition: fvar.hpp:13
constants.hpp
log2.hpp
stan::math::log2
fvar< T > log2(const fvar< T > &x)
Definition: log2.hpp:14
stan::math::fvar
Definition: fvar.hpp:12

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