灰色预测模型的MATLAB-程序及检验程序

灰色预测模型的Matlab程序及检验程序%灰色预测模型程序clearsymsab;c=[ab]';A=[46.232.626.723.020.018.917.516.3];%原始序列B=cumsum(A);%累加n=length(A);fori=1:(n-1)C(i)=(B(i)+B(i+1))/2;end%计算待定参数D=A;D(1)=[];D=D';E=[-C;ones(1,n-1)];c=inv(E*E')*E*D;c=c';a=c(1);b=c(2);%预测往后预测5个数据F=[];F(1)=A(1);fori=2:(n+5)F(i)=(A(1)-b/a)/exp(a*(i-1))+b/a;endG=[];G(1)=A(1);fori=2:(n+5)G(i)=F(i)-F(i-1);endt1=2002:2009;t2=2002:2014;Gplot(t1,A,'o',t2,G)%灰色预测模型检验程序function[q,c,p]=checkgm(x0,x1)%GM检验函数%x0原始序列%x1预测序列%·返回值%q–-相对误差%c--·方差比%p--小误差概率e0=x0-x1;q=e0/x0;s1=var(x0);%qpa=mean(e0);s2=var(e0);c=s2/s1;len=length(e0);p=0;fori=1:lenif(abs(e0(i))0.6745*s1)p=p+1;endendp=p/len;end等级相对误差q方差比C小误差概论PI级0.010.350.95II级0.050.500.80III级0.100.650.70IV级0.200.800.60