Running octave from the sage notebook

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I solved the same problem as follows: in the notebook I ran the SAGE command

os.environ["PATH"]+=": ... path to the binary for octave"

For instance

os.environ["PATH"]+=":/Applications/Octave.app/Contents/Resources/bin"

on my Mac with Octave.app. This gives SAGE the information it needs to find octave.

Instead of writing this in the sage notebook every time you want to use octave, you may write it in your .sage/init.sage file.

Similar to above, the following worked for me from the notebook interface of sage:

os.environ["PATH"]+=":/opt/local/bin"

Octave was installed on my system using MacPorts.

I found that octave.eval('2+2') worked immediately in the notebook, but octave(2+2), required:

octave = Octave()
octave._start()

otherwise it errored with "ValueError: The octave session in which this object was defined is no longer running."

Note: octave.eval returns a string, usually with "ans =", whereas octave() returns a number that I could perform further operations on.

You may want to put octave.quit(True) at the end. I don't understand what is actually going on well, so take my advice with caution.

see also: http://www.sagemath.org/doc/reference/interfaces/sage/interfaces/octave.html

Although the question doesn't explicitly say so, I'm going to guess that the OP is running OSX (as assumed in other answers).

The fundamental problem here is that OSX applications don't read .bashrc or .profile like the shell does. There are several ways to modify the PATH variable for Mac Applications, as described on this stack exchange question. I used the wrapper-script answer by Rene to set my environment for Sage. It has the advantage of providing the same environment to Sage.app that you would expect at the command line, and it works across all notebooks (unlike above answers that modify PATH from within the notebook).

1. Create a file at /Applications/Sage-version.app/Contents/MacOS/Sage.sh with the following text:

   #!/bin/bash
   if [[ -x $HOME/.profile ]]; then
     source $HOME/.profile
   fi
   exec "`dirname \"$0\"`/Sage" "$@"
   

2. Make the file executable

   chmod +x /Applications/Sage-*.app/Contents/MacOS/Sage.sh
   

3. Edit /Applications/Sage-version.app/Contents/Info.plist. Change the CFBundleExecutable to point to the wrapper script

   <key>CFBundleExecutable</key>
   <string>Sage.sh</string>
   

4. Notify LaunchServices that the Info.plist has changed, either by restarting or by running

   /System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -v -f /Applications/Sage-*.app
   

This solution will also address errors running other cell interpreters, such as the LaTeX 'PDFLaTeX does not seem to be installed' error.