Discussion Forum

I am trying to understand how Poincare Map and Phase Portrait work. Correct me if I am wrong:
1) Poincare map: one defines a cut plane, and the coordinates of the crossing point of the particles with this plane are shown. One can not change it to any other expression.
2) Phase portrait: One can define what quantities (such as position of the particle, velocity components, etc) should be plotted, but only at a given *time*

Can these two be combined in some way? I would like to plot (vy/vx,x) not at a fixed time, but on a cut-plane. Is it possible in some way?

Hi,

I actually have the same problem and like to know, if a solution came up during the last two years.

I need a poincare map (I guess it is a line) in a 2D geometry (rotationaly symmetric) to get the position, the velocity and the time, when a particle cuts that line.
Since it is 1D, I guess I need a 1D plot group. But then I don't have the option for a poincaré map.

Cheers,
Gero

Hi Gero, you need to use the "Intersection Point 2D" data set to define a cut line, then use a 1D Plot Group with the Particle plot type. I attach a simple model (made with v5.2a update 2) which does this. You can visualize the cut line by going to the Intersection Point 2D data set and clicking Plot. The 1D plot "Particle Position vs. Velocity" plots the particle position vs. velocity when the cut line is reached and the color represents the time when the particles reached the cut line.

The Intersection Point 2D data set was introduced in V5.2a, so you will need the latest release. There is also a 3D Intersection Point data set which can be used to plot phase portraits of particles on a given cut plane.

Chris