Select
an ODE using the popdown [v] button at lower right. The [Slope Field]
key cycles between showing the slope field in thte graphing window in
white, grey, or not at all.
Choose a stepsize from the columnn of keys at bottom. Choosing [Actual] will cause an RK4 solution with small stepsize to be drawn; [All Euler] will cause the Euler polygons correspsonding to all four of the Euler stepsizes available to be drawn.
The values
of x, y, and F(x,y) are read out to the right. Set an initial condition
by clicking. The current values of x and y are taken as initial conditions
and read out as x0 and y0 to the right and at
the head of the column of values to the left. Rolling the cursor over the graphing window displays
the vector ( i + F(x,y) j ) h where h is is the step size.
Click
on [Start] to begin constructing the Euler polygon. The next segment
of the polygon is drawn, the coordinates of the new vertex are displayed
at the bottom of the column of values at left, and the button then changes
to [Next Step]. Click on [Next Step] to continue the construction of
the Euler polygon.
Click
on [Clear] to clear everything except for the currently chosen initial
condition.
Click
on [Zoom] to toggle between two scales.
©
2001 H. Hohn