Problem withmultitracker and shapedescriptor

[Pedro Alejandro Herve Fernandez Carrera Licenciatura en Cs.Biologicas]

hi to all of you, i´m working with animal path´s, and i´m using the
multitracker plugin, to get the coordinates (X,Y) and to draw the path, but
for my surprise, the path is sometimes upside down.
the other thing, is there a way to get the shapedescriptor gives you data
from 1800 points

bye and thank´s to all