I am attempting a plot where:
x axis: x_1
and y axis: f(x_1)
where x_k is determined by:
x_1 = x_0 - f(x_0)/f'(x_0) (Newton's Method)
So far my program is:
NEWTPATH(t,n)
BEGIN
LOCAL k,w,y;
RECT();
FOR k FROM 1 TO n DO
t-(F1(t)/der(F1(X),X=t))- > w;
F1(w)- > y;
PIXON(w,y);
w- > t;
END;
FREEZE;
END;
The "der" is the derivative funtion.
The program either freezes at the input screen or gives me an "out of bounds" error. I have F1(X) already stored before running the program. Any ideas? Thanks!
Eddie
Edited: 4 Nov 2012, 11:43 a.m.
Have you checked that the derivative is never going null? Just my 2 cents...
I am not sure. When I tried debugging the program the calcualtor goes into "space" when it approaches the loop.
Apparently, der(F1(X),X=t) isn't allowed in a program. I think this is what you meant by the derivative being null. Really dumb not to allow calculus functions.
This is what I have now:
NEWTPATH(g,n)
BEGIN
LOCAL k,w,y,h,d,X;
RECT();
FOR k FROM 1 TO n DO
F1(g)->h;
der(F1(X),X=g)->d;
t-h/d->w;
F1(w)->y;
PRINT(w);
w->t;
END;
END;
Now I get a syntax error on Line 8 every time. Even if I change the der(F1(X),X=g)->d to 1->d, I still get this error. I have no idea where I have the syntax error, I localized all the varaibles, including X.
Edited: 4 Nov 2012, 1:56 p.m.