lgamma_stirling.hpp

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#ifndef STAN_MATH_OPENCL_KERNELS_DEVICE_FUNCTIONS_LGAMMA_STIRLING_HPP
#define STAN_MATH_OPENCL_KERNELS_DEVICE_FUNCTIONS_LGAMMA_STIRLING_HPP
#ifdef STAN_OPENCL
 
#include <stan/math/opencl/stringify.hpp>
#include <string>
 
namespace stan {
namespace math {
namespace opencl_kernels {
 
// \cond
static constexpr const char* lgamma_stirling_device_function
    = "\n"
      "#ifndef STAN_MATH_OPENCL_KERNELS_DEVICE_FUNCTIONS_LGAMMA_STIRLING\n"
      "#define "
      "STAN_MATH_OPENCL_KERNELS_DEVICE_FUNCTIONS_LGAMMA_STIRLING\n" STRINGIFY(
          // \endcond
          double lgamma_stirling(double x) {
            return 0.5 * (M_LN2 + log(M_PI)) + (x - 0.5) * log(x) - x;
          }
          // \cond
          ) "\n#endif\n";  // NOLINT
// \endcond
 
}  // namespace opencl_kernels
}  // namespace math
}  // namespace stan
 
#endif
#endif