有一段代码，请论坛内大神解读一下，完全读不懂：

clc;clear;

[data voxel head]=rest_readfile('structure.nii');

[dim1,dim2,dim3]=size(data);
Data=zeros(dim1,dim2,dim3);
for j=1:dim3
    Data(:,:,j)=data(:,:,dim3-j+1);
    
end
x=Data(:,:,100);

rest_WriteNiftiImage(Data,head,'new.nii')