eof分解用的函数，说明如下：function [EOF,PC,F,diff]=EOFcgx(X)

EOF分解。Xm*n 空间数据维数m，n为时间采样点

返回值EOF为空间模态,PC为时间模态。第一空间模态EOF(:,1),第一时间模态PC(1,:)

返回值F为特征值，diff为误差

-eof decomposition function as follows: function [EOF, PC, F, diff] = EOFcgx (X)

　EOF decomposition. Xm* n spatial dimension m, n is the time of sampling points

　Returns the value EOF spatial modes, PC is the time modes. The first space modal EOF (:, 1), the first time the modal PC (1, :)

　Return value F for eigenvalues, diff for error