Re: Calling Octave from Python

[Maurice Ling]

After changing 2 lines, I've managed to get it running...
1. popen3("/usr/bin/octave -q") to popen2("octave -q","w")
2. result[0] to result

I get the following output, which is wrong

Sum = []

I have no idea what is wrong here. Can anyone help?

At the same time, I'm looking at pexpect (pexpect.sourceforge.net). Does 
anyone have any thoughts on how to interoperate python and octave using 
pexpect?

Thanks.

Cheers
Maurice

Stefan van der Walt wrote:

> The problem is that Octave does not close, so that readlines() cannot
> return.  Try something like
>
> ----
> import os, string
>
> [pwrite, pread] = os.popen3("/usr/bin/octave -q")
>
> pwrite.write("x = [1,2,3];\n")
> pwrite.write("printf('%f\\n', sum(x));\n")
> pwrite.flush()
> pwrite.close()
>
> result = pread.readlines()
> pread.close()
>
> print ("Sum = %s" % result[0])
> ----
>
> Regards
> Stefan
>
> On Mon, Aug 16, 2004 at 12:43:42PM +1000, Maurice Ling wrote:
>  
>
> > Hi,
> >
> > I've been trying to find a way to call Octave from Python and a previous 
> > message in this list uses the following codes...
> >
> > import os
> > import string
> >
> > # make sure to call ocatve with the "quiet" flag
> > [pwrite, pread] = os.popen2("octave -q","w")
> >
> > pwrite.write("x = [1,2,3];\n")
> > pwrite.write("printf('%f\\n', sum(x));\n")
> >
> > # always flush the output to avoid deadlocks
> > pwrite.flush()
> > result = pread.readline()
> > print ("Sum = %f" % string.atof(result))
> >
> > pwrite.close()
> > pread.close()
> >
> >
> > But python freezes itself after "result = pread.readline()". I'm 
> > wondering what is wrong?
> >
> > Thanks
> > Cheers
> > Maurice
> >    
--
Maurice Han Tong LING, BSc(Hons)(MCB), AdvDipComp, SN
Doctor of Philosophy (Science) Candidate, The University of Melbourne
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