disp(' ');
disp(' principal_moi.m   ver 1.0  Nov 30, 2009 ');
disp(' by Tom Irvine  Email: tomirvine@aol.com ');
disp(' ');
disp(' This script calculates the principal moments ');
disp(' of inertia from a rotational inertia matrix');
disp(' ');
%
clear a;
clear Irot;
%
a(1,1)=input(' Enter Ixx ');
a(1,2)=input(' Enter Ixy ');
a(1,3)=input(' Enter Ixz ');
%
disp(' ');
a(2,1)=input(' Enter Iyx ');
a(2,2)=input(' Enter Iyy ');
a(2,3)=input(' Enter Iyz ');
%
disp(' ');
a(3,1)=input(' Enter Izx ');
a(3,2)=input(' Enter Izy ');
a(3,3)=input(' Enter Izz ');
%
disp(' ');
Irot=a
%
[PrincipalDirections PrincipalMoments]=eig(Irot)
TraceIrot=trace(Irot)
TracePM=trace(PrincipalMoments)