[logCoords, logTimetags, underflow] = Datapixx(‘ReadTouchpixxLog’ [, numFrames]);
Upload TOUCHPixx touch panel activity from a Datapixx internal log buffer to the
-“numFrames” is the number of frames to upload, and should not exceed
newLogFrames returned by GetTouchpixxStatus. If numFrames argument is missing,
ReadTouchpixxLog will return all remaining logged data.
-“logCoords” is a 2D array with 2 rows containing x/y touch coordinates, and one
column for each touch datum. Each of the x/y coordinates ranges from 0 to 1. The
coordinate space origin is the top-left corner of the touch panel. When the
panel stops being touched, (0,0) will be returned.
-“logTimetags” is a row vector of acquisition timetags, indicating when the
corresponding touch or release in logData occurred. The timetags are in double
precision seconds since Datapixx powerup. Response times can be calculated by
calling SetMarker() at stimulus onset, then subtracting GetMarker() from the
-“underflow” is set to 1 if calls to ReadTouchpixxLog read too many frames. The
newLogFrames field returned by GetTouchpixxStatus indicates the maximum number
of frames which can be read by ReadTouchpixxLog. If more than this number of
frames is read, an underflow occurs and there will be errors in the logged data.
In addition to returning an underflow flag, the numLogUnderflows field returned
by GetTouchpixxStatus will be incremented.
See Touchpixx*Demo files for examples.