Stan Math Library
2.15.0
reverse mode automatic differentiation
stan
math
fwd
scal
fun
lbeta.hpp
Go to the documentation of this file.
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#ifndef STAN_MATH_FWD_SCAL_FUN_LBETA_HPP
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#define STAN_MATH_FWD_SCAL_FUN_LBETA_HPP
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#include <
stan/math/fwd/core.hpp
>
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#include <boost/math/special_functions/digamma.hpp>
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#include <
stan/math/prim/scal/fun/lbeta.hpp
>
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namespace
stan
{
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namespace
math {
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template
<
typename
T>
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inline
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fvar<T>
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lbeta
(
const
fvar<T>
& x1,
const
fvar<T>
& x2) {
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using
boost::math::digamma
;
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return
fvar<T>
(
lbeta
(x1.
val_
, x2.
val_
),
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x1.
d_
*
digamma
(x1.
val_
)
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+ x2.
d_
*
digamma
(x2.
val_
)
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- (x1.
d_
+ x2.
d_
) *
digamma
(x1.
val_
+ x2.
val_
));
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}
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template
<
typename
T>
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inline
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fvar<T>
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lbeta
(
double
x1,
const
fvar<T>
& x2) {
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using
boost::math::digamma
;
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return
fvar<T>
(
lbeta
(x1, x2.
val_
),
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x2.
d_
*
digamma
(x2.
val_
) - x2.
d_
*
digamma
(x1 + x2.
val_
));
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}
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template
<
typename
T>
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inline
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fvar<T>
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lbeta
(
const
fvar<T>
& x1,
double
x2) {
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using
boost::math::digamma
;
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return
fvar<T>
(
lbeta
(x1.
val_
, x2),
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x1.
d_
*
digamma
(x1.
val_
) - x1.
d_
*
digamma
(x1.
val_
+ x2));
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}
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}
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}
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#endif
core.hpp
stan::math::fvar::d_
T d_
Definition:
fvar.hpp:16
stan
Definition:
log_sum_exp.hpp:8
stan::math::lbeta
fvar< T > lbeta(const fvar< T > &x1, const fvar< T > &x2)
Definition:
lbeta.hpp:15
stan::math::fvar::val_
T val_
Definition:
fvar.hpp:15
lbeta.hpp
stan::math::fvar
Definition:
fvar.hpp:14
stan::math::digamma
fvar< T > digamma(const fvar< T > &x)
Return the derivative of the log gamma function at the specified argument.
Definition:
digamma.hpp:22
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