SSVEP Frequency functions

[JadinTredup]

I am testing the SSVEP stimulus presentation on the new branch and am getting some strange numbers for the frequencies. The problem seems to be due to the following line of code:

frame_rate = np.round(mywin.getActualFrameRate()) # Frame rate, in Hz

For some reason, on my laptop with a 60 Hz monitor, that value returns at above 2000, producing flickers that are way too fast for my monitor.

[JohnGriffiths]

It works ok for me.

I get

Flickering frequencies (Hz): [24.0, 16.0]

But in general I think it would be preferable to specify the flicker frequencies more explicitly (eg adding input arguments for desired frequencies), if poss.

This could be opportunity to do so.

[JadinTredup]

I just tried it on windows and it worked fine for me so it seems to be a problem in Linux. I tried hard-coding the flickering frequencies and it was still having timing issues so it appears to be a psychopy/linux problem. I will try to troubleshoot in their documentation.