1 #ifndef STAN_MATH_PRIM_FUN_CSR_U_TO_Z 2 #define STAN_MATH_PRIM_FUN_CSR_U_TO_Z 3 4 #include <stan/math/prim/err.hpp> 5 #include <stdexcept> 6 #include <vector> 7 8 namespace stan { 9 namespace math { 10 11 /** \addtogroup csr_format 12 * @{ 13 */ 14 15 /** 16 * Return the z vector computed from the specified u vector at the 17 * index for the z vector. 18 * 19 * @param[in] u U vector. 20 * @param[in] i Index into resulting z vector. 21 * @return z[i] where z is conversion from u. 22 * @throw std::domain_error if u is zero length. 23 * @throw std::out_of_range if i is out of range. 24 */ csr_u_to_z(const std::vector<int> & u,int i)25inline int csr_u_to_z(const std::vector<int>& u, int i) { 26 check_range("csr_u_to_z", "i", u.size(), i + 1, "index out of range"); 27 return u[i + 1] - u[i]; 28 } 29 30 } // namespace math 31 } // namespace stan 32 33 #endif 34