Solved issue #1 by exiting function with a warning if passing isoi=0. I decided it is not a sensible stimulus for this experiment. Renamed functions single_optacon_presentation() to single_presentation() and write_optacon_protocol_file() to write_protocol_file(), since 'optacon' label is in the module. Moved functions time_to_frames(), map_apparent_motion() and get_start_rows() from optaconSideways.py to optacon.py because they are not specific to the sideways configuration and can also be used in the normal configuration.