Stan Math Library  2.12.0
reverse mode automatic differentiation
tgamma.hpp
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1 #ifndef STAN_MATH_FWD_SCAL_FUN_TGAMMA_HPP
2 #define STAN_MATH_FWD_SCAL_FUN_TGAMMA_HPP
3 
4 #include <stan/math/fwd/core.hpp>
5 
6 #include <boost/math/special_functions/digamma.hpp>
7 
8 namespace stan {
9  namespace math {
10 
11  template <typename T>
12  inline
13  fvar<T>
14  tgamma(const fvar<T>& x) {
16  using boost::math::tgamma;
17  T u = tgamma(x.val_);
18  return fvar<T>(u, x.d_ * u * digamma(x.val_));
19  }
20  }
21 }
22 #endif
var tgamma(const var &a)
Return the Gamma function applied to the specified variable (C99).
Definition: tgamma.hpp:65
fvar< T > tgamma(const fvar< T > &x)
Definition: tgamma.hpp:14
fvar< T > digamma(const fvar< T > &x)
Definition: digamma.hpp:15

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