[gdal-dev] KyngChaos Frameworks: GDAL's numpy vs Enthought's numpy

William Kyngesburye woklist at kyngchaos.com
Mon Apr 19 11:29:59 EDT 2010

On Apr 19, 2010, at 8:51 AM, K.-Michael Aye wrote:

> Hi!
> I am using quite successfully KyngChaos' Frameworks for GDAL (Thank you, William!) with a custom Python install from python.org on OSX. This install already includes most of the stuff I need for my daily work (numpy,scipy,matplotlib).
> But sometimes I need something special like mayavi2 and for that I have installed the Enthought Python Distribution (luckily for free for academic use), but I can't use the existing GDAL framework because it is based on numpy 1.3 and not on numpy 1.4.
> If I try so, I get a weird 'Bus Error' message and Python just crashes.

GDAL python *should* be able to use a later version of numpy than it was built for, it's only the python side of the interface that it cares about, but I don't know what be happening at compile time that might lock it in to a specific version of numpy, and python can be picky.

If you are including the GDAL framework python folder in the Enthought python path, then numpy 1.3 is also available from there.  But depending on how you added GDAL to the path, numpy might be overridden by Enthought's path.  My installer puts a .pth file in the /Library/Python/2.x/site-packages folder that forces it to the top of the path.  A standard .pth (including the /Library site-packages), oddly, gets added *after* the system paths, so they can't override the system modules.

> Am I guessing right, that the only remedy would be to build GDAL for Numpy 1.4 on my own?
> Or would it be more recommendable to find an old Enthought, that still uses Numpy 1.3?

It's not [Enthought] python that's using numpy, it's GDAL and other python programs.  As long as the python version matches, it should work, though there can be other incompatibilities in different python builds.

> Then I should be able to import gdal into the Enthought's Python, right?
> Any advise would be appreciated!

I generally keep up to date, but I guess I don't check numpy very often and didn't see the v1.4 (interesting, they skipped 1.4.0).  Though that is only an RC release yet, so I may still wait for a final release.

You could try copying my gdal.pth to Enthought's user site-packages, so it should override Enthought's numpy, but that will happen for all other python usage iwth Enthought's python.

I just figured out that I could customize the GDAL python to force it to load the framework copy of numpy, but I'd also then probably isolate that numpy from the python path.  I may try that in the next release.

William Kyngesburye <kyngchaos*at*kyngchaos*dot*com>

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First Pogril: I don't know either.  Wretched, isn't it?

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