Stan Math Library  2.20.0
reverse mode automatic differentiation
digamma.hpp
Go to the documentation of this file.
1 #ifndef STAN_MATH_FWD_SCAL_FUN_DIGAMMA_HPP
2 #define STAN_MATH_FWD_SCAL_FUN_DIGAMMA_HPP
3 
4 #include <stan/math/fwd/meta.hpp>
5 #include <stan/math/fwd/core.hpp>
6 
9 
10 namespace stan {
11 namespace math {
12 
22 template <typename T>
23 inline fvar<T> digamma(const fvar<T>& x) {
24  return fvar<T>(digamma(x.val_), x.d_ * trigamma(x.val_));
25 }
26 } // namespace math
27 } // namespace stan
28 #endif
T d_
The tangent (derivative) of this variable.
Definition: fvar.hpp:50
T val_
The value of this variable.
Definition: fvar.hpp:45
fvar< T > trigamma(const fvar< T > &u)
Return the value of the trigamma function at the specified argument (i.e., the second derivative of t...
Definition: trigamma.hpp:20
This template class represents scalars used in forward-mode automatic differentiation, which consist of values and directional derivatives of the specified template type.
Definition: fvar.hpp:41
fvar< T > digamma(const fvar< T > &x)
Return the derivative of the log gamma function at the specified argument.
Definition: digamma.hpp:23

     [ Stan Home Page ] © 2011–2018, Stan Development Team.