Figure 10. Limit cycle and direction of field for unforced Van der Pol oscillator

From

Some Methods of Analysis of Chaos in Mechanical Systems

Peter Sivák, Ingrid Delyová, Jozef Bocko, Juraj Šarloši

American Journal of Mechanical Engineering. 2014, 2(7), 199-203 doi:10.12691/ajme-2-7-6