GM(1, ）

优化GM(1,1)

主要的改进手段：优化微分方程的初始条件

data ← csvread('D:\matlab2016a\demo\data\air.csv');
num ← length(data);
predictnum ← 6;
train ← data(1:(num - predictnum), :);
test ← data((num - predictnum + 1):end, :);

Y = train(2:end,:);

for i = 1:size(train,1)
X(i,:) = sum(train(1:i,:));
end

for j = 2:size(X,1)
Z(j-1,:) = (X(j,:)+X(j-1,:))/2;
end
B = [-Z,ones(size(Z,1),1)];

**ab = inv(B'*B)B'Y;
a = ab(1,:);
b = ab(2,:);

**for i = 2:num
predict(i-1,:) = (X(e