[visionegg] Re: reading variables for sequences

  • From: Andrew Straw <andrew.straw@xxxxxxxxxxxxxxx>
  • To: visionegg@xxxxxxxxxxxxx
  • Date: Thu, 21 Aug 2003 13:26:20 +0930

Hash: SHA1

the GUI is using only the last stimuli parameters for stimulation (read last x-, y-coordinates, direction-, duration-, andwhateverelse-variable). If someone have a hint/clue how to set correctly a stimulus sequence?

start x         0.0     1       50   #first stimulus
start y 0.0     1       50
velocity        0.0     1       100.0
direction       0.0     1       -45.0
start x         0.0     1       650   #second stimulus
start y 0.0     1       650
velocity        0.0     1       100.0
direction       0.0     1       -235.0

Hi Markus,

You've immediately found the greatest limitation in the current ephys_gui: only a single parameter can be changed over a sequence. All parameters are set in the normal part of the GUI, and the sequence information updates a only single field before each trial in a hierarchical way. Each entry in the sequence information represents a "loop", and the loops are descended into recursively from the top to the bottom. (Your "loops" have only one value, and, in fact, because you have several loop information entries for a single variable, that variable is set and reset multiple times before each trial as the the program recurses into your sequence parameter information.)

I would like to implement a way to link individual elements in the sequence list so that all those variables get updated with each trial. This would allow easily doing what you want. To illustrate what I mean, here's what the GUI would look like for your particular example:

variable  rest N  values       group
start x   0.5  2  50       650 A
start y   0.5  2  50       650 A
direction 0.5  2  -45.0 -235.0 A

(velocity omitted because it's constant for the 2 trials)

What's new is the "group" column, which would let you say that a particular row wasn't an entire loop on its own, but only in conjunction with other members of its group. It's important the rest period and N be the same for all members of the group. Giving the group a name (arbitrarily A in this case) is one way to do what I propose, but it's not essential to the idea -- it could also be implemented with some GUI element linking the rows together.

Unfortunately, I'm very busy with other stuff right now, and I can't say when/if I'll ever get to this. If you want to delve into Tkinter programming, you're welcome to try your hand at this, as it's mainly a GUI issue. This comes with the caveat that I'd really like to move all of the ephys_gui stuff to wxPython/XRC. This change certainly won't happen before the 0.9.5 release, and I don't know when/if it ever will, but it's something you should be aware of before putting much time into programming the Tkinter version of the ephys_gui.



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