[Python] running an existing script

That command they show isn't run from a Python shell. It's run from
either a Unix shell (bash and friends) or a Windows command prompt
(cmd). If you want to run a script, you have to give the path to that
script. ./ means the current directory and .. is the parent directory
if you want to give relative paths, or you can just write out the
whole file path.

nfold.py is a python script -- you can't just type in the name once
inside python and have it work. It would require something like

--> import os
--> os.chdir('path/to/nfold.py') # don't include nfold.py ;)
--> import nfold
--> import sys
--> sys.argv = ["--folds=5", "--data=spambase.data",
... "--spec=spambase.spec", "--roundsP0", "--tree­D_ALL",
... "--generate" ]
...
--> nfold.main() # assuming it has a main function that can be called
# in this manner

and that probably won't work. What you probably want to do is execute
the command "python /path/to/nfold.py --fold=5 ..." (include the
nfold.py this time ). I have no idea how to do that from Matlab.

Good luck!

~Ethan~

If you are actually in a python CLI, at the top of that screen does it
say something like

Python 2.5.4 (r254:67916, Dec 23 2008, 15:10:54) [MSC v.1310 32 bit
(Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.

?

If yes, then what I wrote earlier should actually work (I downloaded
jBoost and looked at the nfold.py script). Here it is again:

--> import os
--> os.chdir('path/to/nfold.py') # don't include nfold.py ;)
--> import nfold
--> import sys
--> sys.argv = ["nfold.py", "--folds=5", "--data=spambase.data",
... "--spec=spambase.spec", "--roundsP0", "--tree­D_ALL",
... "--generate" ]
...
--> nfold.main()

I fixed the sys.argv line from last time.

Good luck!

~Ethan~

Thanks to both of you for your help.

It's getting late here, I'll give it another try tomorrow

I've added the python directories to the environment variable "path"
in my computer (http://showmedo.com/videotutorials/video?
name–0000&fromSeriesID–), which means I can now call python from
the windows DOS-style command prompt.

My formatting must be wrong when calling the nfold.py script to run.
My connad prompt call and the computer's response look like this:

C:\Users\Adam\Desktop\JBOOST\jboost-2.2\jboost-2.2\scripts>nfold.py
nfold.py
File "C:\Users\Adam\Desktop\JBOOST\jboost-2.2\jboost-2.2\scripts
\nfold.py", line 13
print 'Usage: nfold.py <--booster=boosttype> <--folds=number> [--
generate | --dir=dir] [--data=file --spec=file] [--rounds=number --
tree=treetype]'

^
SyntaxError: invalid syntax


What I dont understand is that some of the parameters in the syntax it
printed back are in <> brackets, and others in [] brackets.

I assume this is something a regular python user could notice straight
away.

Please let me know, I'd be very grateful

No, it's a syntax error in the script itself, at least under the
version of Python you're using.
You're probably running Python 3.x, which changed `print` from a
keyword to just a regular function; hence, `print foo` is illegal, and
one must write `print(foo)` instead.
Based on this, I'd say that nfold.py was written for Python 2.x rather
than Python 3.x; so you'll either need to port it to Python 3.x, or
install Python 2.x and run it under that.

Cheers,
Chris

I just tried

nfold.py --booster­aboost --folds=5 --data=spambase.data --
spec=spambase.spec --roundsP0 --tree­D_ALL --generate --dir=C:
\Users\Adam\Desktop\cvdata

in the dos-style command prompt. It didn'g vive a syntax error this
time, it just repeated my command back to me in text. I assume I
called code correctly, but it didn't make a new folder full of data
like it should have.

Which version of jBoost, and which version of Python?

~Ethan~

jboost 2.2, python 2.7

somehow I've just managed to delete all of the code in nfold.py, now
downloading it again...

Thanks a lot, must be getting close now...
I changed the indentation one lines 136-168, and put in the command
window:

nfold.py --booster­aboost --folds=5 --data=spambase.data --
spec=spambase.spec --roundsP0 --tree­D_ALL --generate

no syntax errors this time, it just said:
nfold.py: Your CLASSPATH is not set. You must place jboost.jar in your
CLASSPATH.

is that the chdir() command in python? and can I somehow set that in
the dos command window?

CLASSPATH is an environment variable, jboost.jar is a java file (which
I'm sure you know ;) -- so make sure CLASSPATH is set appropriately for
your system (e.g. 'set CLASSPATH=c:\java\source'), and jboost.jar is
whereever CLASSPATH points to. (I'm not a Java fan, so can't provide
much help in this area.)

~Ethan~

Thanks again Ethan, It did begin to run nfold.py this time, after I
added the environment variable "CLASSPATH" to my system. It threw back
a java error, but I guess this isn;t the right place to be asking
about that

C:\Users\Adam\Desktop\JBOOST\jboost-2.2\jboost-2.2\scripts>nfold.py --
booster­aboost --folds=5 --data=spambase.data --spec=spambase.spec --
roundsP0 --tree­D_ALL --generate
nfold.py --booster­aboost --folds=5 --data=spambase.data --
spec=spambase.spec --roundsP0 --tree­D_ALL --generate
java.lang.NoClassDefFoundError: jboost/controller/Controller
Caused by: java.lang.ClassNotFoundException:
jboost.controller.Controller
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: jboost.controller.Controller. Program
will exit.
Exception in thread "main" k: 0 start:0 end:920
k: 1 start:920 end:1840
k: 2 start:1840 end:2760
k: 3 start:2760 end:3680
k: 4 start:3680 end:4600
*=---------------------------------------------------------------------
=-*
* Fold 0 |
*===========java -Xmx1000M -cp C:\Users\Adam\\Desktop\JBOOST
\jboost-2.2\jboost-2.2\dist jboost.controller.Controller -b Adaboost -
p 3 -a -1 -S trial0 -n trial.spec -ATreeType ADD_ALL -numRounds 500

Looking at the batch file I see a line that modifies the CLASSPATH, so
try this before you run nfold.py (cut across two lines, but it's really
just one):
set CLASSPATH%CLASSPATH%;../dist/jboost.jar;../lib/jfreechart-1.0.10.jar;../lib/jcommon-1.0.8.jar



Good luck!

~Ethan~

Looks like you are using Python 3, but nfold is Python 2. You're being
tripped up by one of the non-compatible changes -- namely, print is now
a function and so requires ().

Looking at nfold.py it seems that rounds and tree are optional, one of
generate or dir is required, if dir is not given then data and spec must
be, and booster and folds are required -- so I'm not really sure why
they chose the mixture of <> and [].


Also, on the version of jBoost I downloaded there is at least one error
on nfolds.py on line 134 -- it should be indented one more level.

Hope this helps.

~Ethan~