A有一个带4个波段的RasterLayer:
>rx<-raster("/media/karimdion/Passport/Essais/po_3804017_bgrn_0000000 tif")
> str(rx)
Formal class 'RasterLayer' [package "raster"] with 12 slots
@ file :Formal class '.RasterFile' [package "raster"] with 12 slots
@ nbands : int 4
@ bandorder : chr "BIL"
@ data :Formal class '.SingleLayerData' [package "raster"] with 13 slots
@ min : num 0
@ max : num 65535
@ band : int 1
@ history : list()
@ title : chr(0)
@ extent :Formal class 'Extent' [package "raster"] with 4 slots
@ xmin: num 655781 …