[visionegg] Re: Recording frame times

Check out VisionEgg.Core.FrameTimer

The VisionEgg.FlowControl.Presentation class already uses this. Essentially, 
you instantiate it, then every time you return from swap_buffers, you do a 
FrameTimer.tick() call. This class is the one that prints the ascii histogram 
at the end of the experiment, so you can use that method and a few other 
helpful ones.

If you are using the VisionEgg.FlowControl.Presentation class with 
collect_timing_info = True (the default), this is being done for you inside 
that class (it's what prints the histogram), but unfortunately, the variable is 
not exposed as a class member. You could change all instances of frame_timer to 
self.frame_timer in the go() method, and then grab that off your presentation 
class in the end, but that's a messy solution for staying up to date with 
Andrew's code.

Cheers,
Dav

On Sep 14, 2011, at 4:00 AM, Longden, Kit wrote:

> Hi,
> 
> I'd like to save the frame times during my code. Would anyone be so kind as 
> to show me the lines I should add to the grating.py demo code (below) to make 
> this happen? I'd be very grateful. 
> 
> Apologies for such an obvious question, it remains unclear to me after 
> checking the archives and documentation, no doubt because of my lack of 
> Python.
> 
> Many thanks,
> 
> Kit
> 
> ****************************
> 
> Kit Longden
> The Krapp Lab: Insect vision, sensory
> integration, motor control and robotics.
> Contact: kit@xxxxxxxxxxxxxx, +44 20759 40717 
> http://www3.imperial.ac.uk/people/c.longden 
> <http://www3.imperial.ac.uk/people/c.longden> 
> Address: Dr Kit Longden, Department of Bioengineering,
> Imperial College London, South Kensington campus, London, SW7 2AZ, U.K.
> 
> ****************************
> 
> #!/usr/bin/env python
> """Sinusoidal grating calculated in realtime."""
> 
> ############################
> #  Import various modules  #
> ############################
> 
> import VisionEgg
> VisionEgg.start_default_logging(); VisionEgg.watch_exceptions()
> 
> from VisionEgg.Core import *
> from VisionEgg.FlowControl import Presentation
> from VisionEgg.Gratings import *
> 
> #####################################
> #  Initialize OpenGL window/screen  #
> #####################################
> 
> screen = get_default_screen()
> 
> ######################################
> #  Create sinusoidal grating object  #
> ######################################
> 
> stimulus = SinGrating2D(position         = ( screen.size[0]/2.0, 
> screen.size[1]/2.0 ),
>                        anchor           = 'center',
>                        size             = ( 300.0 , 300.0 ),
>                        spatial_freq     = 10.0 / screen.size[0], # units of 
> cycles/pixel
>                        temporal_freq_hz = 1.0,
>                        orientation      = 45.0 )
> 
> ###############################################################
> #  Create viewport - intermediary between stimuli and screen  #
> ###############################################################
> 
> viewport = Viewport( screen=screen, stimuli=[stimulus] )
> 
> ########################################
> #  Create presentation object and go!  #
> ########################################
> 
> p = Presentation(go_duration=(5.0,'seconds'),viewports=[viewport])
> p.go()======================================
> The Vision Egg mailing list
> Archives: http://www.freelists.org/archives/visionegg
> Website: http://www.visionegg.org/mailinglist.html

=====================================The Vision Egg mailing list
Archives: http://www.freelists.org/archives/visionegg
Website: http://www.visionegg.org/mailinglist.html

Other related posts: