grad_reg_inc_beta.hpp

Go to the documentation of this file.

#ifndef STAN_MATH_PRIM_FUN_GRAD_REG_INC_BETA_HPP
#define STAN_MATH_PRIM_FUN_GRAD_REG_INC_BETA_HPP
 
#include <stan/math/prim/meta.hpp>
#include <stan/math/prim/fun/beta.hpp>
#include <stan/math/prim/fun/grad_inc_beta.hpp>
#include <stan/math/prim/fun/inc_beta.hpp>
#include <cmath>
 
namespace stan {
namespace math {
 
template <typename T>
void grad_reg_inc_beta(T& g1, T& g2, const T& a, const T& b, const T& z,
                       const T& digammaA, const T& digammaB,
                       const T& digammaSum, const T& betaAB) {
  using std::exp;
  T dBda = 0;
  T dBdb = 0;
  grad_inc_beta(dBda, dBdb, a, b, z);
  T b1 = beta(a, b) * inc_beta(a, b, z);
  g1 = (dBda - b1 * (digammaA - digammaSum)) / betaAB;
  g2 = (dBdb - b1 * (digammaB - digammaSum)) / betaAB;
}
 
}  // namespace math
}  // namespace stan
#endif