Stan Math Library  2.11.0
reverse mode automatic differentiation
lbeta.hpp
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1 #ifndef STAN_MATH_PRIM_SCAL_FUN_LBETA_HPP
2 #define STAN_MATH_PRIM_SCAL_FUN_LBETA_HPP
3 
4 #include <boost/math/tools/promotion.hpp>
5 
6 #include <boost/math/special_functions/gamma.hpp>
7 
8 namespace stan {
9  namespace math {
10 
57  template <typename T1, typename T2>
58  inline typename boost::math::tools::promote_args<T1, T2>::type
59  lbeta(const T1 a, const T2 b) {
60  using boost::math::lgamma;
61  return lgamma(a)
62  + lgamma(b)
63  - lgamma(a + b);
64  }
65 
66  }
67 }
68 
69 #endif
fvar< T > lgamma(const fvar< T > &x)
Definition: lgamma.hpp:15
fvar< T > lbeta(const fvar< T > &x1, const fvar< T > &x2)
Definition: lbeta.hpp:16

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