• The button  will integrate the point selected in the positive direction of time. The integration will last the number of steps defined by the input line  in the Parameters of Integration window. After the integration this button will turn unactive but you will be able to continue integrating the same orbit in the same direction with the button  or integrate it backwards with the button . If you want to start integrating in a different point, you simply need to select it and the window will reconfigure again.
  
• The button  will erase the last orbit you draw. Sometimes, this will cause the plot image to be a little bit distorted. If necessary, press the  button in the plot window to redraw the plot.
  
• The button  will erase all orbits you have drawn.
  
• The button  is used after you manually enter the coordinates of the initial integration point (x0,y0).
  
• A typical view of a plot window after plotting orbits:
  
  
  

• F: integrate orbit forward in time. This key is active after you click an initial point in the phase plane.
  
• B: integrate orbit backward in time. This key is active after you click an initial point in the phase plane.
  
• C: continue forward or backward integration. This key is active after you pressed F or B.
  
• Alt+D: delete last orbit.
  
• Alt+A: delete all orbits.
  

Note: Sometimes it may seem that P4 refuses to assign a point as initial point after you click in the phase plane. This could be caused by the fact that the Limit Cycles window is open. In such a case, a mouse click has a different purpose.

 Back to the main page

 Back to the windows page