| GM(1,1)灰色模型的程序实现function GM1=fungry1(x0) %输入原始数据x0, T7 ^) d( o8 d# ~; w s T=input('T=');%从键盘输入从最后一个历史数据算起的第T时点8 r9 W% w! [2 A2 x& B z% r x1=zeros(1,length(x0));B=zeros(length(x0)-1,2); yn=zeros(length(x0)-1,1);Hatx0=zeros(1,length(x0)+T); Hatx00=zeros(1,length(x0));Hatx1=zeros(1,length(x0)+T); epsilon=zeros(length(x0),1);omega=zeros(length(x0),1); for i=1:length(x0) for j=1:i) D, z" e$ p$ L W' b( h; K x1(i)=x1(i)+x0(j);0 g0 L& G1 w# |* K2 d8 k# i end4 J$ w" \! ?! t. l7 d. x1 J end for i=1:length(x0)-1 B(i,1)=(-1/2)*(x1(i)+x1(i+1)); B(i,2)=1;: M7 j% _1 q8 Q; S0 M# p yn(i)=x0(i+1); end6 g! X4 a/ J9 o- f HatA=(inv(B'*B))*B'*yn % GM(1,1)模型参数估计' e# m* A" o2 ?* R for k=1:length(x0)+T! G* O, V9 T5 _ p Hatx1(k)=(x0(1)-HatA(2)/HatA(1))*exp(-HatA(1)*(k-1))+HatA(2)/HatA(1);; d; b% V7 }' U end, d: Y" o: W) J+ N Hatx0(1)=Hatx1(1);% g- U- J" D' ?2 Z7 D: Y4 S for k=2:length(x0)+T p9 w5 Z7 ^0 t2 o5 }) i4 S" @/ ] Hatx0(k)=Hatx1(k)-Hatx1(k-1);%累计还原得到历史数据的模拟值( O3 a& d; S8 k6 ^ end for i=1:length(x0) %开始模型检验 epsilon(i)=x0(i)-Hatx0(i);: Z6 P" a% H5 \% |' A; J& G" s omega(i)=(epsilon(i)/x0(i))*100; end8 H* s3 I4 @: w' H& O % x0;Hatx0;epsilon;omega; %必要时去掉%得到各种数据- y0 N- d @# N) u; m/ C. ^7 v i% y c=std(epsilon)/std(x0);p=0;, ^8 E9 k+ P# q for i=1:length(x0)6 C3 o. P: t7 e0 f. [; _" a( r( W+ O if abs(epsilon(i)-mean(epsilon))<0.6745*std(x0)# A$ R& }; Z3 c) y p=p+1; end end# O( ^6 D6 i9 _ p=p/length(x0)6 ~6 B/ L1 Z7 y3 \* d; c if p>0.95 & c<0.35 disp('The model is good,and the forecast is:'), disp(Hatx0(length(x0)+T))5 ~: L! s! r9 ?7 d elseif p>0.85 & c<0.59 _, Z) z' R/ c2 E# Y- F disp('The model is eligibility,and the forecast is:'),& h1 I+ `. }& } ^/ n; {5 ]8 L disp(Hatx0(length(x0)+T)) elseif p>0.7 & c>0.65; c' Q% x$ w. z$ Z. ]4 I; c; N disp('The model is not good,and the forecast is:'),8 x( ?- ]7 K0 }8 E( m8 i" E% L disp(Hatx0(length(x0)+T))0 q. Q; S' \% o1 R M else p<=0.7 & c>0.65 disp('The model is bad and try again') end for i=1:length(x0)6 j" _% ~+ d5 ~9 O/ b- p Hatx00(i)=Hatx0(i); end z=1:length(x0); plot(z,x0,'-',z,Hatx00,':') %将原始数据和模拟值画在一个图上帮助观察+ e1 `; \! S2 t( w' c3 ~1 @- j# d text(2,x0(2),'History data: real line')- m) g j8 A& Z9 m9 M text(length(x0)/2,Hatx00(length(x0))/2,'Simulation data:broken line') endT=input('T=');%从键盘输入从最后一个历史数据算起的第T时点????是指什么啊,请大哥们,大姐们教一下,我急用,请快,谢谢我的初始值x0=[1.620938526- E# b5 b6 @" p( C j 0.07925621, z7 K- P( w" D. D: Z8 I; P- p 0.052318818 0.0412525027 d1 O+ G* i1 } 0.0218004796 @8 \" {/ g& c+ p, m: Z7 @) U 0.053132975 0.089908836* Q/ l6 N2 v( s D0 A% B 0.109153219 0.079331832 0.3421925982 h/ q, ?- L& Z3 l2 ]0 o$ T6 d" U 0.099718142 0.135194823 0.109274037 0.08152013 0.067876355 0.0647068432 W. \7 l( [! n5 o- j `* d8 f 0.0555621979 _# l$ _5 z4 ?' m 0.050848544& B8 @7 @9 K B4 m& L7 `% j1 a. ] ]'; |

| 欢迎光临 数学建模社区-数学中国 (http://www.madio.net/) | Powered by Discuz! X2.5 |