I've been using editrpy to analyze my laps versus replays I pulled off
the 'net and I've noticed something a bit strange. In looking at the
graphs of the data (speed vs. distance) there is a peak in the middle of
the corners that really doesn't make much sense. The speed is at its
lowest on turn-in then climbs to a peak around the apex and then falls
off until the exit before beginning to go up on the ensuing straight.
If you give it much thought, this seems pretty counter intuitive. I was
looking through one of the files that comes with editrpy that explains
the icr2 replay format and it says that the car positions are given in a
format with one coordinate being the distance along the centerline of
the track and the other as a horizontal offset (positive or negative)
from the centerline.
Two points:
1) Is editrpy just looking at the "vertical" (position along
the track) component of the cars position? If so, this would seem to
explain the jumps in speed during the corners, as the car would cut
through the apex, effectively covering "more" of the track relative to
the centerline.
2) Does anyone know how to pull the "real world" x-y coordinates out of
the track data file? If this could be done, it would be possible to
write an improved version of editrpy that would be able to measure speed
more accurately, as well as stuff like lateral acceleration. I'd think
that some of the folks who work with the track converters must know the
file formats pretty well - would they mind sharing that information for
this purpose?
Please respond by email as I only occasionally read the group.
Thanks in advance,
Nick
