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Normalize a CRS specification

normalize_crs.Rd

Validates a coordinate reference system supplied in any of the common shorthand formats and returns a canonicalized string that terra recognizes. Useful for checking a CRS value before passing it to get_layer or resolve_to_bbox.

Usage

normalize_crs(crs)

Arguments

crs

One of:

  • An integer EPSG code (e.g. 4326).

  • A character string: "EPSG:4326", a bare numeric string ("4326"), a PROJ string, or a WKT string.

  • NULL — treated as "no CRS" and returns TRUE with no "crs" attribute.

Value

A length-1 logical. On success (TRUE) carries a "crs" attribute containing the normalized CRS string. On failure (FALSE) carries a "message" attribute describing why the input was not recognized.

Examples

r <- normalize_crs(4326)
#> Error in normalize_crs(4326): could not find function "normalize_crs"
isTRUE(r)          # TRUE
#> Error: object 'r' not found
attr(r, "crs")     # "EPSG:4326"
#> Error: object 'r' not found

r2 <- normalize_crs("32611")
#> Error in normalize_crs("32611"): could not find function "normalize_crs"
attr(r2, "crs")    # "EPSG:32611"
#> Error: object 'r2' not found

r_bad <- normalize_crs("not-a-crs")
#> Error in normalize_crs("not-a-crs"): could not find function "normalize_crs"
isTRUE(r_bad)      # FALSE
#> Error: object 'r_bad' not found
attr(r_bad, "message")
#> Error: object 'r_bad' not found