void RTOp_sparse_sub_vector(RTOp_index_type global_offset, RTOp_index_type sub_dim, RTOp_index_type sub_nz, const RTOp_value_type values[], ptrdiff_t values_stride, const RTOp_index_type indices[], ptrdiff_t indices_stride, ptrdiff_t local_offset, int is_sorted, struct RTOp_SparseSubVector *sub_vec)