Using slopef.m

We want to plot the slopefield of the first order ODE $x' \,=\, f(t,x)$ over a user-designated window $a \,\leq\, t \,\leq\, b$, $c \,\leq\, x \,\leq\, d$.

1. Make the appropriate changes in init.m.

   ftx = '$f(t,x)$'; (RHS of $x' \,=\, f(t,x)$)
   initax = [$a$,$b$,$c$,$d$]; (desired window size)

   Save then type init in the command window to initialize the variables (or copy-and-paste in the Emporium).
   (Unles otherwise specified, we will use N = 20; as originally written in init.m.

2. Type slopef(ftx,N)

3. If the resulting plot does not show all of the general behavior for the ODE solution, you may have to choose new $t$ and/or $x$-values for initax, then do Items 1 and 2 again.