Special CRS values

The CRS handling in the wk package requires two sentinel CRS values. The first, wk_crs_inherit(), signals that the vector should inherit a CRS of another vector if combined. This is useful for empty, NULL, and/or zero-length geometries. The second, wk_crs_auto(), is used as the default argument of crs for constructors so that zero-length geometries are assigned a CRS of wk_crs_inherit() by default.

wk_crs_inherit()

wk_crs_longlat(crs = NULL)

wk_crs_auto()

wk_crs_auto_value(x, crs)

Arguments

crs

A value for the coordinate reference system supplied by the user.

x

A raw input to a construuctor whose length and crs attributte is used to determine the default CRS returned by wk_crs_auto().

Examples

wk_crs_auto_value(list(), wk_crs_auto())
#> <wk_crs_inherit>
wk_crs_auto_value(list(), 1234)
#> [1] 1234
wk_crs_auto_value(list(NULL), wk_crs_auto())
#> NULL