Vector Fields -- Help
Select an autonomous system using the pulldown menu at right. Some selections have parameters which can be set by sliders at upper right.
The graphing window at left shows a portion of the selected vector field, and the trajectory (in cyan) through an initial point (marked in red). The motion of the solution along this trajectory can be animated using the [>>] key or using the time slider. The [<<] key resets t = - 15.
Rolling the cursor over the graphing window causes a readout (in red, at upper right) of the coordinates. With [Set point] selected, depressing the mousekey creates a portion of the trajectory though the red point, which remains when the mousekey is released. With [Drag axes] selected, a pale gray center point is displayed, and the vector field can be dragged with a depressed mousekey.
A slider at bottom left controls a zoom feature affecting both the graphing window and the vertical axes of the time series child windows.
Selecting [x(t)] or [y(t)] causes separate windows to pop up, containing graphs of the x or y as functions of t. The progress of the solution is indicated by a yellow diamond on these graphs. Rolling the cursor over these windows creates readouts of the values of (t,x) or (t,y).
The [Vector Field] key toggles three intensities of the vector field display.
2009 H. Miller, D. Jerison, and J.-M. Claus