On Mar 17, 2011, at 9:27 PM, Jimin Park wrote:

Could somebody please give me some help?
I tried putting

stat.file = $out.stat

line in the params file, to see if it makes any difference, but no luck there.
There is only one out.stat file in ecj's root folder and this never gets changed.
When I run the tutorial, is it supposed to create a new out.stat file somewhere?
I would like to see the results of my GP in a tree like form visually.

It's got to be there somewhere, not sure where your IDE is hiding it.

Instead of $out.stat, you might try an explicit path.  For example, if you're on a Mac, you might try

stat.file = /Users/jimin/Desktop/out.stat

(or something like that)

Or if you're on Windows you might try something like:

stat.file = c:\documents and settings\jimin\desktop\out.stat

(or maybe...)

stat.file = c:/documents and settings/jimin/desktop/out.stat

(I'm not sure how Java interacts with paths in Windows)

Also your file doesn't have to be named out.stat, so you could try:

stat.file = $my.file

And then search for "my.file" on your hard drive.

I tried to print the result in C-ish format like in the tutorial.
I got the following error.

Parameter no longer used.  See GPTree.java for details.
PARAMETER: pop.subpop.0.species.ind.tree.0.c
   ALSO: gp.tree.c
SYSTEM EXITING FROM ERRORS

Just thought I should put it up.
Maybe the tutorial is out of date and doesn't work
with the new ECJ version?

Thanks, I'll check the tutorial.  The parameter has now changed to:

pop.subpop.0.species.ind.tree.0.print-style=c

There are two options you can try also:

pop.subpop.0.species.ind.tree.0.c-operators=false
pop.subpop.0.species.ind.tree.0.c-variables=false

The tutorial should work just fine still; though it's true the current version has made a bunch of improvements.