[Maxima-discuss] unkind error return from rk() with stiff o.d.e.

[Edwin W. <woo...@ch...>]

In a previous post, I complained about the "unkind"
error return of rk(..) with a stiff o.d.e. (many pages of
error messages).

For an example of a  "kind" return with a contributed
method, use rkf45:
---------------------------
(%i2) load(rkf45);
(%o2) 
"C:/PROGRA~1/MAXIMA~3.2/share/maxima/5.31.2/share/contrib/rkf45/rkf45.mac"
(%i9) stiff : rkf45([y2, 1000*y2*(1-y1^2) - y1],[y1,y2],[2,0],[t,0,30])$
Warning: rkf45: Integration stopped at x = 8.7296685 (stiff problem?)
                Iterations limit has been reached. Check if differential
                equations/initial conditions are given correctly, reduce
                accuracy, and/or increase maximum number of steps.

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Ted Woollett