Merge branch 'dev' of https://github.com/tqchen/xgboost into dev

Conflicts:
	demo/rank/mq2008.conf
	demo/rank/runexp.sh
	regrank/xgboost_regrank_obj.h

demo/rank/README

@@ -1 +1,13 @@
-The dataset for ranking demo is from LETOR04 MQ2008 fold1,http://research.microsoft.com/en-us/um/beijing/projects/letor/letor4download.aspx
+Instructions:
+The dataset for ranking demo is from LETOR04 MQ2008 fold1, 
+You can use the following command to run the example
+
+
+Get the data: ./wgetdata.sh
+Run the example: ./runexp.sh
+
+
+
+
+
+

demo/rank/mq2008.conf

@@ -2,10 +2,8 @@
 # choose the tree booster, 0: tree, 1: linear
 booster_type = 0 
 
+# so far, we have pairwise rank
 objective="rank:pairwise"
-#objective="rank:softmax"
-#objective="rank:map"
-#objective="rank:ndcg"
 
 # Tree Booster Parameters
 # step size shrinkage
@@ -16,8 +14,7 @@ bst:gamma = 1.0
 bst:min_child_weight = 0.1
 # maximum depth of a tree
 bst:max_depth = 6
-eval_metric = "ndcg"
-eval_metric = "map"
+
 # Task parameters
 # the number of round to do boosting
 num_round = 4

demo/rank/wgetdata.sh

@@ -0,0 +1,4 @@
+#!/bin/bash
+wget http://research.microsoft.com/en-us/um/beijing/projects/letor/LETOR4.0/Data/MQ2008.rar
+unrar x MQ2008.rar
+mv -f MQ2008/Fold1/*.txt .