解方程的二分法 matlab 程序

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解方程的二分法  matlab 程序  （ x^3-3*x^2+6*x-1=0）

% Bisection.m
function[k,x,f_value]=Bisection(f,a,b,eps1,eps2,N)
5 u& j: L! Q* Y+ {$ G0 ?fprintf('k ,a ,b ,x, f\n')
, v# A+ _' J4 I& B# z0 j( Lfor k=1:N
- W. E% @' e: p( a    x=(a+b)/2;
8 ]- D6 |$ k0 s+ q/ R8 u    f_value=f(x);
9 h+ S% o& _4 K6 `" s. H# J, ?: v    fprintf( '%3d, %10.9f, %10.9f, %10.9f,%10.9f,\n'...
; s( c% M' @( `8 t4 V/ b% k      ,k ,a ,b ,x, f_value)
0 X1 {5 A, a  E: \1 l, h    if abs(f_value)< eps1||0.5*(b-a)<eps2
5 Q( R; B  K2 L4 J    return
    else
        if f(x)*f(a)<0
. ]. g# p+ W6 [9 I          b=x;
7 {6 }) o0 f  {5 n' n& M  Q        else
; w3 R- n. H5 ~5 A% }4 @, k          a=x;
) s) I7 v" O' \7 D9 z' T        end
/ Z7 h/ l/ E" g6 c        if k== N
          warning ('算法超出最大迭代數!')   
        end
6 l% k; G  h$ _/ d# @  g! O, [    end

% examlpe7.m
a=0; b=1;
eps1=1e-4;eps2=1e-4;
3 }. V- G1 j4 ^0 f! }4 S/ z3 B8 ? N=300;
f=@ (x) (x^3-3*x^2+6*x-1);
Hfun=@Bisection;
7 |* h$ \& y% U[k,x,f_value]= feval(Hfun, f,a,b,eps1,eps2,N);

運行結果
>> examlpe7
k ,a ,b ,x, f
3 d. G' R3 g" V& O" l5 z' w  1, 0.000000000, 1.000000000, 0.500000000,1.375000000,
6 q3 B& q* o: z6 M. w+ S2 L  2, 0.000000000, 0.500000000, 0.250000000,0.328125000,
  3, 0.000000000, 0.250000000, 0.125000000,-0.294921875,
% t" u, v  O' k* Q4 e  4, 0.125000000, 0.250000000, 0.187500000,0.026123047,
$ g( ]$ C% x% \  5, 0.125000000, 0.187500000, 0.156250000,-0.131927490,
# O- a. ~3 r! M0 V4 R: y3 L  6, 0.156250000, 0.187500000, 0.171875000,-0.052295685,
  7, 0.171875000, 0.187500000, 0.179687500,-0.012936115,
! C) X7 S! R: N  8, 0.179687500, 0.187500000, 0.183593750,0.006630838,
. v& T+ R5 K7 ~  b  9, 0.179687500, 0.183593750, 0.181640625,-0.003143273,
+ t2 o4 \1 A  X, N% T 10, 0.181640625, 0.183593750, 0.182617188,0.001746121,
11, 0.181640625, 0.182617188, 0.182128906,-0.000697991,
- m$ U5 Y. m+ K$ M( H 12, 0.182128906, 0.182617188, 0.182373047,0.000524211,
13, 0.182128906, 0.182373047, 0.182250977,-0.000086854,