Download an elevation raster from internet
The function getelev
allows for the download of an elevation raster
from internet. It downloads the "Global Multi-resolution Terrain Elevation
Data 2010" from our server. The file was originally downloaded from:
https://topotools.cr.usgs.gov/gmted_viewer/viewer.htm
and converted into a
tif file by us. The function getelev
uses the generic function
downloadfile
that can also be used to download directly other files.
This raster needs further processing with the function prepelev
and can then be passed to isoscape
.
getelev(path = NULL, overwrite = FALSE, verbose = interactive())
path |
A string indicating where to store the file on the hard drive (without the file name!) |
overwrite |
A logical indicating if an existing file should be re-downloaded |
verbose |
A logical indicating whether information about the
progress of the procedure should be displayed or not while the function is
running. By default verbose is |
If the argument "path" is not provided, the file will be stored in the
current working directory. The function can create new directories, so you
can also indicate a new path. If the package tools is
installed, the integrity of the elevation raster is tested after a call to
getelev
. In case of corruption, try downloading the file again,
specifying overwrite = TRUE to overwrite the corrupted file.
## To download the high resolution ## raster in your current working ## directory, just type: ## getelev()
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