In this case, a sketch of the phase portrait may give qualitative information about the dynamics of the system, such as the limit cycle of the Van der Pol oscillator shown in the diagram.
Ludwig van Beethoven | Vincent van Gogh | Van Morrison | Van Halen | Der Spiegel | Der Rosenkavalier | Gus Van Sant | Der Ring des Nibelungen | Anthony van Dyck | Rotenburg an der Fulda | Ellen van Dijk | Van Diemen's Land | Van | Martin Van Buren | Eddie Van Halen | Spittal an der Drau | Melvin Van Peebles | Limburg an der Lahn | Jean-Claude Van Damme | Jan van Eyck | Armin van Buuren | Weiden in der Oberpfalz | Van Cliburn | Townes Van Zandt | Van, Turkey | Dillingen an der Donau | Dave Van Ronk | Van Dyke Parks | Van der Graaf Generator | The Dick Van Dyke Show |
He was a close friend of Dutch physicist Balthasar van der Pol, whose work on nonlinear self-oscillating dynamical systems (see van der Pol oscillator) he extended and popularized among electrical engineers, mathematicians, and economists.