请问matlab怎样通过Acr_Mat产生空间权重矩阵？本人菜鸟，望详细帮助，非常感谢！

另，运行：
>> filename = '..\shape_files\china';
results = shape_read(filename);

会出现
??? shp_read: Unable to open shape file
Error in ==> shape_read at 60
[cartex,cartey,xmin,xmax,ymin,ymax,nvertices,nparts,xc,yc] = shp_read(filename);

请问这是什么原因，为什么shape-read不能用？