Check if a crs is NULL or NA

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)
#> [1] TRUE
fm_crs_is_null(27700)
#> [1] FALSE
fm_crs_is_null(fm_crs())
#> [1] TRUE
fm_crs_is_null(fm_crs(27700))
#> [1] FALSE
fm_crs_is_null(fm_crs(oblique = c(1, 2, 3, 4)))
#> [1] FALSE
fm_crs_is_null(fm_crs(oblique = c(1, 2, 3, 4)), crsonly = TRUE)
#> [1] TRUE
fm_crs_is_null(fm_crs(27700, oblique = c(1, 2, 3, 4)))
#> [1] FALSE
fm_crs_is_null(fm_crs(27700, oblique = c(1, 2, 3, 4)), crsonly = TRUE)
#> [1] FALSE