fm_crs_is_null: Check if a crs is NULL or NA

In fmesher: Triangle Meshes and Related Geometry Tools

Check if a crs is NULL or NA

Description

Methods of checking whether various kinds of CRS objects are NULL or NA. Logically equivalent to either is.na(fm_crs(x)) or is.na(fm_crs(x, oblique = NA)), but with a short-cut pre-check for is.null(x).

Usage

fm_crs_is_null(x, crsonly = FALSE)

## S3 method for class 'fm_crs'
is.na(x)

Arguments

x	An object supported by fm_crs(x)
crsonly	For crs objects with extended functionality, such as fm_crs() objects with oblique information, crsonly = TRUE only checks the plain CRS part.

Value

logical

Functions

• fm_crs_is_null(): Check if an object is or has NULL or NA CRS information. If not NULL, is.na(fm_crs(x)) is returned. This allows the input to be e.g. a proj4string or epsg number, since the default fm_crs() method passes its argument on to sf::st_crs().

• is.na(fm_crs): Check if a fm_crs has NA crs information and NA obliqueness

See Also

fm_crs(), fm_CRS(), fm_crs_is_identical()

Examples

fm_crs_is_null(NULL)
fm_crs_is_null(27700)
fm_crs_is_null(fm_crs())
fm_crs_is_null(fm_crs(27700))
fm_crs_is_null(fm_crs(oblique = c(1, 2, 3, 4)))
fm_crs_is_null(fm_crs(oblique = c(1, 2, 3, 4)), crsonly = TRUE)
fm_crs_is_null(fm_crs(27700, oblique = c(1, 2, 3, 4)))
fm_crs_is_null(fm_crs(27700, oblique = c(1, 2, 3, 4)), crsonly = TRUE)

fmesher documentation built on Aug. 9, 2025, 1:10 a.m.