Hi!
I wanted to check whether there is a difference between “t” and a self-generated clock (myClock) in the ‘beginn routine’ tab of a code component.
Therefore I generated 3 variables: t, myClock (generated in Begin Routine tab of a code component), and the difference between them t - myClock.getTime()
When I put these three variables in three text components (set every frame) then I get a difference score between t and myClock (always around 0.015…ms) which should not be the case because both should start at the beginning of a routine?
I am preparing a timing experiment and at the moment I don’t know what can be recommended in this case.
0.015s is one frame so I suspect that one clock is starting before frame 1 and the other is starting at the end of frame 1 (assuming you record both times in the End Routine).
I find that t in End Routine is usually about 15ms greater than the recorded reaction time of a keyboard component, so I tend to record reaction times in Each Frame code instead of End Routine when I have mouse/touchscreen responses.
Thank you for the reply!
t is higher.
In my case t is the variable that psychopy generates at the beginning of a routine (Clocks and trial counters — Workshops for PsychoPy 2021 2021)
I recorded t and myClock in Each Frame.
Based on your response it takes 1 frame for PsychoPy to generate myClock?
So t which should start at beginning of a routine and myClock which should also start at the beginning are slightly different. A mixture of t and myClock.getTime() in code of Each Frame would potentially be problematic.