Re: Symbolic doesn't works after loading

[Colin Macdonald]

On 2018-07-17 12:12 PM, maby200 wrote:
> Hello, I am trying to use symbolic in octave.
> First, downloaded and installed symbolic with:
>           pkg install -forge symbolic
>           pkg load symbolic
> Then, started to write some code
>           syms x
> and next thing appeared:
>
> Initializing communication with SymPy using a popen2() pipe.
> "python" no se reconoce como un comando interno o externo,
> programa o archivo por lotes ejecutable.
> error: Cannot run the Python executable "python"
>      Python and SymPy are needed for most Symbolic features.
>      Is Python installed?  Is your "path" configured correctly?
> error: called from
>      assert_have_python_and_sympy at line 24 column 5
>      python_ipc_popen2 at line 78 column 5
>      python_ipc_driver at line 59 column 13
>      python_cmd at line 164 column 9
>      valid_sym_assumptions at line 38 column 10
>      assumptions at line 82 column 7
>      syms at line 97 column 13
>
> I have Python 2.7 installed.
> Is anything wrong with it?

1.  Maybe "python.exe" is not in your path?

> "python" no se reconoce como un comando interno o externo,
> programa o archivo por lotes ejecutable.
> error: Cannot run the Python executable "python"

2.  What OS?  If Windows, see 
https://github.com/cbm755/octsympy/wiki/Notes-on-Windows-installation

3.  If GNU/Linux or Mac, what does does "which python" say at the 
command prompt?

4.  Try "setenv PYTHON python2"

5.  Upcoming version 2.7.0 has a new "sympref diagnose" command that can 
debug some of this for you.  You could download the .tar.gz file from 
https://sourceforge.net/p/octave/package-releases/346/ and try that.

best,
Colin