灰色模型

zhang6880258

我在matlab中用GM（1,1）模型预测，可是误差太大了。请高手指点~~~~~~~~~~

1. clear1 I# s% O6 x\" a6 y* Z) q
   
2. syms a b;  z0 I/ h\" T; G) B
   
3. c=[a b]';\" X) D8 W$ q  U9 p5 g4 \: T
   
4. A=[539.658590944408,544.467335019023,543.118901615168,541.395536784412,539.719603563031,538.320685053971,536.799895148485,539.869612431029,534.915223499512,544.533125668254];
   - S# k* ?2 j% |9 X/ }\" ~6 n' B
5. B=cumsum(A);
   / g8 S0 a) D, D: @
6. n=length(A);* o# v$ J; q2 p/ Q: @
   
7. for m=1:(n-1)1 Y; P' \3 T' \, m( f6 D, L
   
8.     C(m)=(B(m)+B(m+1))/2;
   ' o) }4 k' ^( {
9. end+ @4 z# }% u5 b& i7 y0 X' t
   
10. D=A;
    4 o\" x, n8 n5 d8 y3 a7 u0 E
11. D(1)=[];  \7 `\" n9 x1 M\" u, D( Y8 o8 d
    
12. D=D';! r6 `2 D& ~+ M2 G3 ], w
    
13. E=[-C;ones(1,n-1)];0 {  j6 b. e( j/ K) M9 a9 _# a( q; M
    
14. c=inv(E*E')*E*D;! c. r# n) G8 C$ z5 I
    
15. c=c';7 D/ F# Z7 f  u# g\" ~) q6 Q
    
16. a=c(1);+ d2 ]% G6 S+ K9 g8 o8 H
    
17. b=c(2);) I; m: _! T  e3 j3 d! O
    
18. F=[];# m3 X7 T1 K, K8 x* }
    
19. F(1)=A(1);6 Z) e\" f5 Q- o; U9 z; Q  n( Z$ o
    
20. for m=2:(n+10)
    7 s. \* x$ A9 S4 R
21.     F(m)=(A(1)-b/a)/exp(a*(m-1))+b/a;
    8 C( {2 E4 \$ W, }7 m! ~  g- d
22. end; a6 c  I+ ?( V- [7 K, p( i
    
23. G=[];5 a7 Y: m& c5 l( ?
    
24. G(1)=A(1);5 o# e8 f, X7 p
    
25. for m=2:(n+2)
    5 i; X& A6 c+ c- P7 q5 `2 C
26.     G(m)=F(m)-F(m-1);
    3 c/ `. l0 K0 E7 w
27. end
    6 e, {$ q: z  K$ T
28. t1=1:10;
    ! t0 e- z1 r5 z0 T2 k\" Q
29. t2=1:12;
    6 I. v$ k7 R; N( z# `* V  m
30. plot(t1,A,'r',t2,G,'g')7 |0 p, n( R- w$ r) i
    

复制代码

wssl103050