Get the value of the anisotropy exponent for a tile of elevation

get_zeta_raster(DEM, tiles, raster_resolution, .zeta_df = NULL, ...)

Arguments

DEM	an elevation raster
tiles	a `RasterLayer` or a `SpatialPolygons` to tiles `DEM`
raster_resolution	`numeric` the resolution of `rstr` in meters
.zeta_df	null or a data.frame with column zeta and a number of rows equals to the number of cells of tiles
...	to pass the `vertical_accuracy` argument to `get_zeta_df()`

stack of raster of size tiles with anisotropy exponent values and a number of layers equals to the number of column in .zeta_df