I got this image. Mr. Clemens i search lots of things but , couldn’t get it what is stim channel and also event? Why do we need them? I read that to create epochs is important create event but what is that actually ??
To add on the tutorial, which is definitely where you should look into, you do have a channel 'STIM' which looks flat (zeros) and probably has a couple of spikes at some points (events). To confirm you do have events (non-zero values) you can either:
Plot with raw.copy().pick_types(stim=True).plot() but pick only the stim channel and navigate/search interactively for events with the left/right arrow keys of your keyboard.
Plot with matplotlib:
from matplotlib import pyplot as plt
Or simply look for non-zero values:
import numpy as np
data = raw.get_data(picks='STIM')[0, :]
That will already tell us more about what is actually stored on your 'STIM' channel.
If you have an all-zero stim channel then something went wrong during recording. What kind of data do you have? What is the original file format? Did you check if you already have annotations in raw.annotations?