how to access the data?

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Ka Lok Kam
2014-04-30
2014-05-02
  • Ka Lok Kam
    Ka Lok Kam
    2014-04-30

    Dear Developers,

    In the User Manuel, it says that we can access the data by using following codes (in the chapter 'Topographica Command Line'

    measure_or_pref()
    (mat,bbox)=topo.sim['V1'].sheet_views['OrientationPreference'].view()
    print mat
    print bbox.lbrt()

    By running this code, I get an AttributeError.

    (I also try topo.sim['V1'].views['maps']['OrientationPreference'], but then I do not know how to go further.)

    So I think the attribute 'sheet_views' is not used anymore so now I do not know how to access those data during simulation (like Orientation preference, OS, Fourier transform and afferent weights in V1 or LGN). Can anyone give me an idea to do this?

    Kalok

     
  • You're right; this information is out of date. We are currently completely revamping our support for accessing such data, making it vastly more powerful and easy to use. Once we're done, we'll update the documentation appropriately. Meanwhile, I think you can use:

    topo.sim.V1.views.maps.OrientationPreference.top.data
    topo.sim.V1.views.maps.OrientationPreference.top.bounds

    but I'll check with the developers whether this is the right way to do it at present.

     
  • Yes, that documentation should be updated. As rightly pointed out the new way of accessing preference map measurements is via:

    topo.sim.V1.views.maps.OrientationPreference.top.data
    topo.sim.V1.views.maps.OrientationPreference.top.bounds

    Apologies for the confusion, we're currently in the process of a complete redesign and will be releasing new tutorials and documentation in the coming weeks and months. Until then we're happy to help with any problems.

     
    • Ka Lok Kam
      Ka Lok Kam
      2014-05-02

      Dear Phillip and James,

      Thanks for help. But the command

      topo.sim.V1.views.maps.OrientationPreference.top.data

      gives me a matrix with only real numbers. But I think the orientation map is composed by complex numbers (its phase and strength). So does the output only give us the phase (form 0 to Pi) of the map? Because I also want to get the power spectrum of the map, the strength is also necessary. Could you tell me how to access that?

      Thank you,
      Kalok

       
  • We store the data as real numbers, but you can combine it into a complex representation if you need to for certain calculations. The strength is accessed as:

    topo.sim.V1.views.maps.OrientationSelectivity.top.data

     
    • Ka Lok Kam
      Ka Lok Kam
      2014-05-02

      James, Thanks for helping me a lot.