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Opposite colors for my stimuli


I am using python since may 2018 and I’m learning to use psychopy. I try to create a dot that should be red but, when I set the color to red, the dot is displaying in blue. When I set it to black, the dot is displaying in white. I tried to change the opacity of my fixmark but it isn’t working either. Does anyone have a clue on how to fixe it?

I’m coding with VSCode on Mac(version 10.11.6) and I installed psychopy 1.90.3.

Thank you!

Show us the relevant code please.

Hi and thank you for the quick reply!

I created two files:

DISPSIZE=(1440, 900) #Display of my screen. A tuple

#doit etre en RGB. Psychopy interprete de meme.

FGC=(-1,-1,-1) #foreground color textes et lignes.

BGC=(0,0,0) #background color. '''
'''#Window is a class
from psychopy.visual import Window, GratingStim, ImageStim
from constants import DISPSIZE, FGC
from psychopy.core import wait #une fct
import numpy as numpy

disp=Window(size=DISPSIZE, units='pix',fullscr=True)

fixmark=GratingStim(win=disp,mask="circle",size=15,pos=[-4,0],sf=3,colorSpace='rgb255') #(disp,radius=6,edges=64,lineColor=FGC,fillColor=FGC)
fixmark.setColor([255,255,255]) #gives an inversed color





We can’t easily cut and paste your code if it isn’t formatted as code (e.g. straight quotes become curly quotes).

I’m not really sure what the issue is here. Perhaps things will be clearer if you change the spatial frequency to be 0.03 rather than 3:

Yes, I think the spatial frequency is the issue here. It is so high that the output is a constant, evaluated at the trough of the grating - changing the phase to be 0.5 recovers the desired colour.

I think a Circle is better suited to the purpose.

1 Like

Terrific! Thank you so much for your help!

Oh terrific! Thank you so much for your help and I’ll definitely pay attention for the code formatting!