Re: Octave and OctSympy

[Colin Macdonald]

On 28/03/15 02:03, Chuck Allison wrote:
> I’m not sure you may be able to assist me, but I am trying to use the
> symbolic package (OctSympy) on Octave 3.8.0 on Mac OS X Yosemite. I
> have installed the latest version from GitHub. I also have Python
> 2.7.9 installed with sympy also installed. For some reason, Octave
> loads an older version of python (2.7.6) and can’t find sympy. Here
> is the error stream I get in Octave:
>
> > > pkg load symbolic symbols
> error: 'symbols' undefined near line 1 column 1
> > > syms x
> OctSymPy v2.1.0: this is free software without warranty, see source.
> Initializing communication with SymPy using a popen2() pipe. Some
> output from the Python subprocess (pid 11830) might appear next.
> warning: fopen: file found in load path Python 2.7.6 (default, Sep  9
> 2014, 15:04:36) [GCC 4.2.1 Compatible Apple LLVM 6.0
> (clang-600.0.39)] on darwin Type "help", "copyright", "credits" or
> "license" for more information.
> > > > > > > Traceback (most recent call last):
> File "<stdin>", line 2, in <module> ImportError: No module named
> sympy Traceback (most recent call last): File "<stdin>", line 2, in
> <module> NameError: name 'sympy' is not defined Traceback (most
> recent call last): File "<stdin>", line 1, in <module> NameError:
> name 'sympy' is not defined extractblock: read an error back from
> python str1 = <type 'exceptions.ImportError'>
>
> str2 = No module named sympy
>
> error: error reading back from python error: called from: error:
> /Users/chuck/octave/symbolic-2.1.0/private/extractblock.m at line
> 166, column 7 error:
> /Users/chuck/octave/symbolic-2.1.0/private/extractblock.m at line 51,
> column 14 error:
> /Users/chuck/octave/symbolic-2.1.0/private/extractblock.m at line 13,
> column 8 error:
> /Users/chuck/octave/symbolic-2.1.0/private/python_ipc_popen2.m at
> line 82,column 7 error:
> /Users/chuck/octave/symbolic-2.1.0/private/python_ipc_driver.m at
> line 30,column 13 error:
> /Users/chuck/octave/symbolic-2.1.0/python_cmd.m at line 120, column
> 9 error:   /Users/chuck/octave/symbolic-2.1.0/@sym/sym.m at line 279,
> column 5 error: evaluating argument list element number 3 error:
> /Users/chuck/octave/symbolic-2.1.0/syms.m at line 157, column 9
>
>
> Would you happen to know how to fix this issue, whether there is a
> way to tell octsympy to load the correct version of Python, for
> example?
>
> Thank you!

Hi Chuck,

1.  You could try:

>> sympref python /path/to/your/preferred/python

Let me know if that works.  If you open a terminal and type "python" 
which python interpreter does it start?  I.e., it could be a problem 
with your path.

2.  If you install it instead with "pkg install -forge symbolic" from 
within Octave, does that change anything?  (probably not).

3.  I've not personally tested it on a Mac, but others have told me it 
works so its at least possible!

Colin

P.s., I've CC'd address@hidden, hope that's ok.  (But CC me on 
replies as I'm not subscribed).