Orbital classification in an N-body bar
  The dynamics and evolution of any galactic structure are strongly influenced
by the properties of the orbits that constitute it. In this paper, we compare
two orbit classification schemes, one by Laskar (NAFF) , and the other by
Carpintero and Aguilar (CA), by applying both of them to orbits obtained by
following individual particles in a numerical simulation of a barred galaxy. We
find that, at least for our case and some provisos, the main frequencies
calculated by the two methods are in good agreement: for $80\%$ of the orbits
the difference between the results of the two methods is less than $5\%$ for
all three main frequencies. However, it is difficult to evaluate the amount of
regular or chaotic bar orbits in a given system. The fraction of regular orbits
obtained by the NAFF method strongly depends on the critical frequency drift
parameter, while in the CA method the number of fundamental frequencies
strongly depends on the frequency difference parameter $L_{\rm r}$ and the
maximum integer used for searching the linear independence of the fundamental
frequencies. We also find that, for a given particle, in general the projection
of its motion along the bar minor axis is more regular than the other two
projections, while the projection along the intermediate axis is the least
regular.
