c=inv(E*E'*E*D; c=c'; a=c(1; b=c(2;
%预测后续数据 F=[]; F(1=A(1; for i=2:(n+5
F(i=(A(1-b/a/exp(a*(i-1+b/a; end G=[]; G(1=A(1; for i=2:(n+5 G(i=F(i-F(i-1; end
t1=1997:2004; t2=1997:2009;
G;a,b %输出预测值、发展系数和灰色作用量 plot(t1,A,'o',t2,G %原始数据与预测数据的比较
%灰色预测模型检验程序 --相对误差检验 Q=[]; for i=1:n e(i=A(i-G(i; Q(i=abs(e(i/A(i; end q=mean(Q,2; q B : clear syms a b; c=[a,b]';
A=[46.2 32.6 26.7 23.0 20.0 18.9]; B=cumsum(A; %原始数据累加 n=length(A; for i=1:(n-1
C(i=(B(i+B(i+1/2; %%%%% 生成累加矩阵 end %%% 计算待定参数的值 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; %预测后续数据 F=[]; F(1=A(1; for i=2:(n+3 F(i=(A(1-b/a/exp(a*(i-1+b/a; end G=[]; G(1=A(1; for i=2:(n+3 G(i=F(i-F(i-1; end t1=1:6; t2=1:9; G,a,b %输出预测值、发展系数和灰色作用量 plot(t1,A,'o',t2,G %原始数据与预测数据的比较 %灰色预测模型检验程序--相对误差检验 Q=[]; for i=1:n e(i=A(i-G(i; Q(i=abs(e(i/A(i; end q=mean(Q,2; q