racket/collects/plot/demos/fit-demo-1.ss
2005-05-27 18:56:37 +00:00

24 lines
564 B
Scheme

(require (lib "plot.ss" "plot"))
(define x-vals (build-list 15 (lambda (x) x) ))
(define errors (build-list 15 (lambda (x) 1)))
(define (fun x)
(* 3 (exp (* x -1 1.32))))
(define z-vals (map fun x-vals))
(define (gues-fun x a b)
(* a (exp (* x -1 b))))
(define params
(fit gues-fun
((a 1) (b 1))
(map vector x-vals z-vals errors)))
(plot (mix
(points (map vector x-vals z-vals))
(line (lambda (x)
(apply gues-fun x (fit-result-final-params params)))))
(x-min -1) (x-max 20)
(y-min -1) (y-max 10))