R: Sets or retrieves projection attributes on classes extending...

is.projected {sp} | R Documentation

## Sets or retrieves projection attributes on classes extending SpatialData

### Description

Sets or retrieves projection attributes on classes extending SpatialData; set or retrieve option value for error or warning on exceedance of geographical coordinate range, set or retrieve option value for exceedance tolerance of geographical coordinate range. Note that only “+proj=longlat +ellps=WGS84” is accepted for geographical coordinates, which must be ordered (eastings, northings); the “+ellps=” definition must be given (or expanded internally from a given “+datum=” value) for recent versions of the PROJ.4 library, and should be set to an appropriate value.

### Usage

    is.projected(obj)
    proj4string(obj)
    proj4string(obj) <- value
    get_ll_warn()
    get_ll_TOL()
    get_ReplCRS_warn()
    set_ll_warn(value)
    set_ll_TOL(value)
    set_ReplCRS_warn(value)

### Arguments

`obj` | An object of class or extending Spatial-class
`value` | For `proj4string` CRS object, containing a valid proj4 string; attempts to assign an object containing “longlat” to data extending beyond longitude [-180, 360] or lattitude [-90, 90] will be stopped. For `set_ll_warn` a single logical value, if FALSE (default) error on range exceedance, if TRUE, warning. For `set_ll_TOL` the value of the power of `.Machine$double.eps` (default 0.25) to use as tolerance in testing range exceedance. `set_ReplCRS_warn` may be used to turn off warnings issued when changing object CRS with the `proj4string` replacement method (by setting `value=FALSE`).

### Details

proj4 strings are operative through CRAN package rgdal. For strings defined as “longlat”, the minimum longitude should be -180, the maximum longitude 360, the minimum latitude -90, and the maximum latitude 90. Note that the `proj4string` replacement method does not project spatial data - for this use `spTransform` methods in the rgdal package.

### Value

`is.projected` returns a logical that may be `NA`; `proj4string` returns a character vector of length 1.

### Author(s)

Edzer Pebesma, edzer.pebesma@uni-muenster.de

### See Also

CRS

[Package sp version 1.4-0 Index]