diff --git a/regrank/xgboost_regrank_sample.h b/regrank/xgboost_regrank_sample.h
deleted file mode 100644
index fa4d82f84..000000000
--- a/regrank/xgboost_regrank_sample.h
+++ /dev/null
@@ -1,123 +0,0 @@
-#ifndef _XGBOOST_REGRANK_SAMPLE_H_
-#define _XGBOOST_REGRANK_SAMPLE_H_
-#include <vector>
-#include"../utils/xgboost_utils.h"
-
-namespace xgboost {
-    namespace regrank {
-        namespace sample {
-            
-            /*
-            * \brief the data structure to maintain the sample pairs
-            *        similar to the adjacency list of a graph
-            */
-            struct Pairs {
-
-                /*
-                * \brief constructor given the start and end offset of the sampling group
-                *        in overall instances
-                * \param start the begin index of the group
-                * \param end the end index of the group
-                */
-                Pairs(int start, int end) :start_(start), end_(end){
-                    for (int i = start; i < end; i++){
-                        std::vector<int> v;
-                        pairs_.push_back(v);
-                    }
-                }
-                /*
-                * \brief retrieve the related pair information of an data instances
-                * \param index, the index of retrieved instance
-                * \return the index of instances paired
-                */
-                std::vector<int> GetPairs(int index) const{
-                    utils::Assert(index >= start_ && index < end_, "The query index out of sampling bound");
-                    return pairs_[index - start_];
-                }
-
-                /*
-                * \brief add in a sampled pair
-                * \param index the index of the instance to sample a friend
-                * \param paired_index the index of the instance sampled as a friend
-                */
-                void push(int index, int paired_index){
-                    pairs_[index - start_].push_back(paired_index);
-                }
-
-                std::vector< std::vector<int> > pairs_;
-                int start_;
-                int end_;
-            };
-
-            /*
-            * \brief the interface of pair sampler
-            */
-            struct IPairSampler {
-                /*
-                * \brief Generate sample pairs given the predcions, labels, the start and the end index
-                *        of a specified group
-                * \param preds, the predictions of all data instances
-                * \param labels, the labels of all data instances
-                * \param start, the start index of a specified group
-                * \param end, the end index of a specified group
-                * \return the generated pairs
-                */
-                virtual std::vector< std::pair<int, int> > GenPairs(const std::vector<float> &preds,
-                const std::vector<float> &labels,
-                int start, int end) = 0;
-
-            };
-
-            enum{
-                BINARY_LINEAR_SAMPLER
-            };
-
-            /*! \brief A simple pair sampler when the rank relevence scale is binary
-            *         for each positive instance, we will pick a negative
-            *         instance and add in a pair. When using binary linear sampler,
-            *         we should guarantee the labels are 0 or 1
-            */
-            struct BinaryLinearSampler :public IPairSampler{
-                virtual std::vector< std::pair<int, int> > GenPairs(const std::vector<float> &preds,
-                const std::vector<float> &labels,
-                int start, int end) {
-                    std::vector< std::pair<int, int> > ans;
-                    return ans;
-                }
-            };
-
-
-            /*! \brief Pair Sampler Wrapper*/
-            struct PairSamplerWrapper{
-            public:
-                inline void AssignSampler(int sampler_index){
-
-                    switch (sampler_index){
-                    case BINARY_LINEAR_SAMPLER:sampler_ = &binary_linear_sampler; break;
-                    default:utils::Error("Cannot find the specified sampler");
-                    }
-                }
-                
-                ~PairSamplerWrapper(){ delete sampler_; }
-
-                std::vector< std::pair<int, int> > GenPairs(const std::vector<float> &preds,
-                    const std::vector<float> &labels,
-                    int start, int end){
-                    utils::Assert(sampler_ != NULL, "Not config the sampler yet. Add rank:sampler in the config file\n");
-                    return sampler_->GenPairs(preds, labels, start, end);
-                }
-            private:
-                BinaryLinearSampler binary_linear_sampler;
-                IPairSampler *sampler_;
-            };
-
-            
-
-        }
-    }
-
-
-    
-
-}
-#endif