Changes between Version 32 and Version 33 of FAQ

Jul 6, 2012, 3:20:09 PM (8 years ago)



  • FAQ

    v32 v33  
    1111'''[#WheredoIfindApplicationspecificFAQs Where do I find Application specific FAQs?]'''
     13'''[#SetupsaysIhaven'tgotthedependenciesinstalled(scipy,numpy,etc.),butIdo! Setup says I haven't got the dependencies installed (scipy, numpy, etc.), but I do!]'''
    2425Each application has its own wiki that contains a extensive information and links. Some are still under construction but will be included when they are released in beta. FAQs for each can be found here:  [simulation:FAQ Simulation FAQs], [rfpulse:FAQ RFPulse FAQs], Analysis FAQs
     27=== Setup says I haven't got the dependencies installed (scipy, numpy, etc.), but I do! ===
     28[This was in response to a Windows user question] - One reason for this is that you may have more than one Python version installed, and when you install a Python package for one of our dependencies, it is installed to only one Python version at a time. In other words, if you have Python 2.5, 2.6 and 2.7 on your computer and you install matplotlib, it is installed for just one of those Pythons. It isn't installed "globally". If you want matplotlib to be available to all 3 versions of Python, you have to install it 3 times, once for each Python.
     30Under Windows, when you install a Python package from an installer (an EXE that you double click), it can see that you have multiple Pythons and it guesses which Python under which it should install itself. It gives you the option to change this guess during the installation, but it's easy to overlook. So, for example, you may installed matplotlib and scipy to a different Python than the one you're trying to use with Vespa.
     32Vespa uses the first Python it finds in your path. If you open a command prompt and type 'set path', it will show you the current path, and that will tell you which Python comes first. Another way to find out which Python is first in your path is with this command:
     35   python -c "import sys; print sys.executable"
     38That should print something like "c:\python26\python.exe".
     40You can test whether or not Python can import a package with a command like this:
     43   python -c "import matplotlib"
     46If matplotlib is installed, that will return silently. If it's not installed, you'll get a loud & clear import error like this:
     49   python -c "import this_does_not_exist"
     50   Traceback (most recent call last):
     51     File "<string>", line 1, in <module>
     52   ImportError: No module named this_does_not_exist
     55Those commands should give you the tools you need to figure out what is installed where. However, if the Vespa installer says that matplotlib isn't installed, it definitely is not for that version of Python. The Vespa installer just tries the same test suggested above: import something and see whether or not it fails.