IsoriX: getelev – R documentation

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getelev

Download an elevation raster from internet

Description

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.

Usage

getelev(path = NULL, overwrite = FALSE, verbose = interactive())

Arguments

`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 `TRUE` if users use an interactive R session and `FALSE` otherwise. If a `numeric` is provided instead, additional information about the download will be provided if the number is greater than 1.

Details

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.

Source

https://topotools.cr.usgs.gov/gmted_viewer/viewer.htm

Examples

## To download the high resolution
## raster in your current working
## directory, just type:
## getelev()

IsoriX

Isoscape Computation and Inference of Spatial Origins using Mixed Models

v0.8.2

GPL (>= 2)

Authors

Alexandre Courtiol [aut, cre] (<https://orcid.org/0000-0003-0637-2959>), François Rousset [aut] (<https://orcid.org/0000-0003-4670-0371>), Marie-Sophie Rohwaeder [aut], Stephanie Kramer-Schadt [aut] (<https://orcid.org/0000-0002-9269-4446>)

Initial release