terra: isLonLat – R documentation

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isLonLat

Check for longitude/latitude crs

Description

Test whether a SpatRaster or SpatVector has a longitude/latitude coordinate reference system (CRS), or perhaps has one. That is wen the CRS is unknown ("") but the x coordinates are within -181 and 181 and the y coordinates are within -90.1 and 90.1. For a SpatRaster you can also test if it is longitude/latitude and "global" (covers all longitudes).

The form isLonLat is depracated. Use is.lonlat

Usage

## S4 method for signature 'SpatRaster'
is.lonlat(x, perhaps=FALSE, warn=TRUE, global=FALSE)

## S4 method for signature 'SpatVector'
is.lonlat(x, perhaps=FALSE, warn=TRUE)

## S4 method for signature 'SpatRaster'
isLonLat(x)

## S4 method for signature 'SpatVector'
isLonLat(x)

Arguments

`x`	SpatRaster or SpatVector
`perhaps`	logical. If `TRUE` and the crs is unknown, the method returns `TRUE` if the coordinates are plausible for longitude/latitude
`warn`	logical. If `TRUE`, a warning is given if the CRS is unknown or when the CRS is longitude/latitude but the coordinates do not match that
`global`	logical. If `TRUE`, the method tests if the raster covers all longitudes (from -180 to 180 degrees) such that the extreme columns are in fact adjacent

Value

logical

Examples

r <- rast()
is.lonlat(r)
is.lonlat(r, global=TRUE)

crs(r) <- ""
is.lonlat(r)
is.lonlat(r, perhaps=TRUE, warn=FALSE)

crs(r) <- "+proj=lcc +lat_1=48 +lat_2=33 +lon_0=-100 +ellps=WGS84"
is.lonlat(r)

terra

Spatial Data Analysis

v1.2-10

GPL (>= 3)

Authors

Robert J. Hijmans [cre, aut] (<https://orcid.org/0000-0001-5872-2872>), Roger Bivand [ctb] (<https://orcid.org/0000-0003-2392-6140>), Karl Forner [ctb], Jeroen Ooms [ctb] (<https://orcid.org/0000-0002-4035-0289>), Edzer Pebesma [ctb] (<https://orcid.org/0000-0001-8049-7069>)

Initial release

2021-05-12