Dear Alexandre, There are some additional parameters to allow situations like yours to work. Any SinGrating2D has the parameters phase_at_t0 t0_time_sec_absolute which hopefully have self-explanatory names. The idea is that current phase is calculated according to: if p.ignore_time: phase = p.phase_at_t0 else: t_var = VisionEgg.time_func() - p.t0_time_sec_absolute phase = t_var*p.temporal_freq_hz*-360.0 + p.phase_at_t0 Thus, setting these two parameters should allow you to do exactly what you want. If you're dealing with 2 computers and thus 2 clocks, there may be an issue synchronizing them so that your control computer can tell the stimulus generation computer what time t0_time_sec_absolute should be. Also, you may be able to set the ignore_time parameter to True and control phase/temporal freq purely through the phase_at_t0 parameter. In that case, you'd probably want to write a function controller that handled setting phase_at_t0 locally on the stimulus generation computer rather than sending phase updates over the network. I hope that helps, Andrew Alexandre Santos wrote: > Hi Andrew, > > We have been using gratingTCP.py to remotely display a stimulus > synchronized with the microscope image acquisition. The program > controlling the image acquisition sends the description of the > stimulus to the computer producing the stimulus. The stimulus itself > consists of a grating that is first static (tf=const(0)), and then > moves across the screen (tf=const(1.5)). We coded the two phases of > the stimulus (static grating, moving grating) with the same > parameters, except obviously for the temporal frequency. > > Our problem is that once the moving grating is presented, it shows a > different phase from the static grating, which causes a undesired > "flicker". This happens even if we define an equal phase parameter for > both stimuli . > > Do you have an idea on how we could avoid the flicker, and have a > continuous transition from static to moving grating? > > All the best, > Alexandre Santos > ====================================== > The Vision Egg mailing list > Archives: //www.freelists.org/archives/visionegg > Website: http://www.visionegg.org/mailinglist.html -- Dr. Andrew D. Straw California Institute of Technology http://www.its.caltech.edu/~astraw/ ====================================== The Vision Egg mailing list Archives: //www.freelists.org/archives/visionegg Website: http://www.visionegg.org/mailinglist.html