Introduction - If you have any usage issues, please Google them yourself
Poincare mapping sections in the phase space properly (should be beneficial to observe the system and changes in movement characteristics, such as the cross-section can not be tangent trajectory, but also can not contain rail line) to select a cross-section, in this section for a total of conjugate variables, such as x1 and X.1 take a fixed value, call this cross-section for the Poincare section, the phase space of the continuous trajectory of the point of intersection with the Poincare cross-section to become cut-off point.