Add a layer to a Raster* object or drop a layer from a RasterStack or RasterBrick. The object returned is always a RasterStack (unless nothing to add or drop was provided, in which case the original object is returned).
addLayer(x,...)dropLayer(x, i,...)
Arguments
x: Raster* object
i: integer. Indices of the layers to be dropped
...: Additional arguments. The layers to add for addLayer. None implemented for dropLayer)