Thank you for such a wonderful tutorial. Could you please let me know how I can install it on a Windows system?

Thank you

> NLTK will create temporary files that contains the training set (in a format acceptable for MEGAM)
> NLTK will spawn a subproces that will call, via command line, the MEGAM (.opt) executable, providing the location of the temporary file as parameters (along with some other parameters).
> The MEGAM executable will run over the temporary file, and when done, creates an output dump of the results and exits.
> NLTK will resume by consuming the MEGAM output dump and creating the trained classification object.

In the past I have actually identified the exact command line statements that NLTK tries to run (on the MEGAM executable), and ran it directly myself (without NLTK, on a temporary file I created).

So it seems to me that, for some reason, the user associated with the execution context of the command line statement is unable to spawn a subprocess, which will be used to execute the MEGAM executable.

Maybe try changing the rights on the MEGAM executable (.opt file), or the location where NLTK creates temporary files, maybe one of them is a read-only?… something along that execution flow described above doesn’t seem to be configured correctly, although I am struggling to tell exactly which bit.

You could always try to execute MEGAM directly, without NLTK, and see what happens!

Hope this helps!

Traceback (most recent call last):
File “classifying.py”, line 492, in
me_classifier = MaxentClassifier.train(train_feats, algorithm=’megam’)
File “/usr/local/lib/python2.7/dist-packages/nltk/classify/maxent.py”, line 319, in train
gaussian_prior_sigma, **cutoffs)
File “/usr/local/lib/python2.7/dist-packages/nltk/classify/maxent.py”, line 1522, in train_maxent_classifier_with_megam
stdout = call_megam(options)
File “/usr/local/lib/python2.7/dist-packages/nltk/classify/megam.py”, line 167, in call_megam
p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
File “/usr/lib/python2.7/subprocess.py”, line 679, in __init__
errread, errwrite)
File “/usr/lib/python2.7/subprocess.py”, line 1249, in _execute_child
raise child_exception
OSError: [Errno 13] Permission denied

Any hints to solve it?

Thanks in advance.
Marco

Apologies for the delayed response, I was away for Christmas and New Year.

The error you are getting seems to be in relation to finding the megam file, two reasons that might be happening (that I could think of for now anyway):

> The file path is incorrect: how about you try using the full path to the megam.opt file, rather than a relative path, when calling the nltk.config_megam() function, just to see if that fixes things. Could be as simple as that.

> There is a mismatch between the architecture the file is compiled to, and the Python/Ubuntu versions running: The file is compiled to 64-Bit, are you sure the rest of the dependant are too?

Cheers!