抄録
Numerical experiment on breakdown of KAM tori is carried out for the motion of a simple pendulum.
As a time step of the difference equation increases, integral curve in the phase plane for a certain fixed initial value deviates from the exact solution until it diverges.
Whole curve of a periodic solution is mapped into a rather curious figure with a few blank regions, before it diverges for larger time steps.
Comparison with the simple harmonic motion as well as the effect of a resistance term on torus are also shown.
