Add LETOR MQ2008 for rank demo

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()
+
+