I am using few data sets available online and trying to visualize tree. However, it does not let me visualize tree option at all. Could anyone please guide me how to get the tree diagram in weka by using data sets available online?
Look here http://maya.cs.depaul.edu/classes/ect584/weka/classify.html, for example.
First you have to fit your decision tree (I used the J48 classifier on the iris
dataset), in the usual way. In the results list panel (bottom left on Weka explorer), right click on the corresponding output and select "Visualize tree" as shown below.
If you have installed the Prefuse plugin, you can even visualize your tree on a more pretty layout.