Phi.hpp

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#ifndef STAN_MATH_OPENCL_KERNELS_DEVICE_FUNCTIONS_PHI_HPP
#define STAN_MATH_OPENCL_KERNELS_DEVICE_FUNCTIONS_PHI_HPP
#ifdef STAN_OPENCL
 
#include <stan/math/opencl/stringify.hpp>
#include <string>
 
namespace stan {
namespace math {
namespace opencl_kernels {
// \cond
static constexpr const char* phi_device_function
    = "\n"
      "#ifndef STAN_MATH_OPENCL_KERNELS_DEVICE_FUNCTIONS_PHI\n"
      "#define STAN_MATH_OPENCL_KERNELS_DEVICE_FUNCTIONS_PHI\n" STRINGIFY(
          // \endcond
          inline double Phi(double x) {
            if (x < -37.5) {
              return 0;
            } else if (x < -5.0) {
              return 0.5 * erfc(-M_SQRT1_2 * x);
            } else if (x > 8.25) {
              return 1;
            } else {
              return 0.5 * (1.0 + erf(M_SQRT1_2 * x));
            }
          }
          // \cond
          ) "\n#endif\n";  // NOLINT
// \endcond
 
}  // namespace opencl_kernels
}  // namespace math
}  // namespace stan
 
#endif
#endif