Argument when initializing Weka

Question

In the Download page of Weka there is a recommendation to initialize the. weka jar file with the following argument -Xmx1000M. But I don’t understand what the argument will change the moment Weka is executed. Since the initialization works even without the argument, what is the difference?

Answer 1

This parameter sets the maximum size of the Heap available for Weka to use.

You can read what Heap is here.