逼近函数

yaoyuan4102

function f = Legendre(y,k,x0)
syms t;
4 s; S$ q+ i# e8 ~1 tP(1:k+1) = t;
( K6 d+ J! \* P3 Q! v3 W& S) H$ vP(1) = 1;
P(2) = t;
c(1:k+1) = 0.0;
c(1)=int(subs(y,findsym(sym(y)),sym('t'))*P(1),t,-1,1)/2;
6 |8 }' s4 @' Q! H, Kc(2)=int(subs(y,findsym(sym(y)),sym('t'))*P(2),t,-1,1)/2;
1 g: _  O4 P% p8 Bf = c(1)+c(2)*t;
5 g- [5 z$ _8 z8 n# @$ Sfor i=3:k+1
! w% @. Y+ @$ z0 K- j, p. r6 P    P(i) = ((2*i-3)*P(i-1)*t-(i-2)*P(i-2))/(i-1);
    c(i) = int(subs(y,findsym(sym(y)),t)*P(i),t,-1,1)/2;
; S' p* v! {# g$ t    f = f + c(i)*P(i);
   
, C3 w% U/ b4 |2 J5 R7 }6 q    if(i==k+1)
        if(nargin == 3)
            f = subs(f,'t',x0);
4 V0 m& I  J9 P8 H" C" |        else
            f = vpa(f,6);
5 O1 C$ ~7 D3 }        end
    end
1 Z- J8 [' Q. F5 {8 cend

Kadyniost

？？？？？

coolistone

顶顶顶顶顶顶顶顶顶顶顶顶的

hjl19890710

lihan厉害厉害厉害厉害厉害

hjl19890710

好 dwadedcsargtg

昝斌

这是什么哦？

zqyzixin

呵呵，非常感谢，很好很强大