Add LETOR MQ2008 for rank demo

demo/rank/README

@@ -1,13 +1 @@
-Demonstrating how to use XGBoost accomplish regression tasks on computer hardware dataset https://archive.ics.uci.edu/ml/datasets/Computer+Hardware
-
-Run: ./runexp.sh
-
-Format of input: LIBSVM format
-
-Format of ```featmap.txt: <featureid> <featurename> <q or i or int>\n ```:
-  - Feature id must be from 0 to number of features, in sorted order.
-  - i means this feature is binary indicator feature
-  - q means this feature is a quantitative value, such as age, time, can be missing
-  - int means this feature is integer value (when int is hinted, the decision boundary will be integer)
-
-Explainations: https://github.com/tqchen/xgboost/wiki/Regression
+The dataset for ranking demo is from LETOR04 MQ2008 fold1,http://research.microsoft.com/en-us/um/beijing/projects/letor/letor4download.aspx

demo/rank/mq2008.conf

@@ -10,6 +10,7 @@ objective="rank:pairwise"
 #objective="lambdarank:map"
 #objective="lambdarank:ndcg"
 
+num_feature=50
 # Tree Booster Parameters
 # step size shrinkage
 bst:eta = 1.0 
@@ -26,10 +27,10 @@ num_round = 2
 # 0 means do not save any model except the final round model
 save_period = 0 
 # The path of training data
-data = "toy.train" 
+data = "mq2008.train" 
 # The path of validation data, used to monitor training process, here [test] sets name of the validation set
-eval[test] = "toy.eval" 
+eval[test] = "mq2008.vali" 
 # The path of test data 
-test:data = "toy.test"      
+test:data = "mq2008.test"      
 
 

demo/rank/runexp.sh

@@ -0,0 +1,11 @@
+python trans_data.py train.txt mq2008.train mq2008.train.group
+
+python trans_data.py test.txt mq2008.test mq2008.test.group
+
+python trans_data.py vali.txt mq2008.vali mq2008.vali.group
+
+../../xgboost mq2008.conf
+
+../../xgboost mq2008.conf task=pred model_in=0002.model
+
+../../xgboost mq2008.conf task=dump model_in=0002.model name_dump=dump.raw.txt

demo/rank/trans_data.py

@@ -0,0 +1,40 @@
+import sys
+
+def save_data(group_data,output_feature,output_group):
+    if len(group_data) == 0:
+	return
+
+    output_group.write(str(len(group_data))+"\n")
+    for data in group_data:
+	output_feature.write(data[0] + " " + " ".join(data[2:]) + "\n")
+
+if __name__ == "__main__":
+    if len(sys.argv) != 4:
+        print "Usage: python trans_data.py [Ranksvm Format Input] [Output Feature File] [Output Group File]"
+	sys.exit(0)
+
+    input = open(sys.argv[1])
+    output_feature = open(sys.argv[2],"w")
+    output_group = open(sys.argv[3],"w")
+    
+    group_data = []
+    group = ""
+    for line in input:
+	if not line:
+	    break
+	if "#" in line:
+	    line = line[:line.index("#")]
+        splits = line.strip().split(" ")
+	if splits[1] != group:
+	    save_data(group_data,output_feature,output_group)
+	    group_data = []
+	group = splits[1]
+	group_data.append(splits)
+
+    save_data(group_data,output_feature,output_group)
+
+    input.close()
+    output_feature.close()
+    output_group.close()
+
+