Example

Create a phase plane plot for the system

$$\mbox{\bf x}' \;=\; \left[\begin{array}{*{2}{c}}1 & 1 \\ 4 &... ..._1 \,\leq\, 2.5, \\ -2.5 \,\leq\, x_2 \,\leq\, 2.5 \end{array}$$ (6)

(Note that this is a linear, homogeneous system with constant coefficients.)

1. Change only the following in initsys.m

   initax = [-2.5, 2.5, -2.5, 2.5];

   A = [1, 1; 4, 1]

   eqnname = 'cclin';

   However make sure there are entries for each of the other variables. (e.g., B = []; is okay.) Save initsys.m, then type initsys (or copy-and-paste at the Emporium).
2. Type pplane2d

The plot can be reduced and placed in one of the four corners of the screen using the subplot command. Type help subplot at the MATLAB command prompt for more information.