Method: Proj::Conversion#initialize

Defined in:
lib/proj/conversion.rb

#initialize(value, context = nil) ⇒ Conversion

Instantiates an conversion from a string. The string can be:

  • proj-string,

  • WKT string,

  • object code (like “EPSG:4326”, “urn:ogc:def:crs:EPSG::4326”, “urn:ogc:def:coordinateOperation:EPSG::1671”),

  • Object name. e.g “WGS 84”, “WGS 84 / UTM zone 31N”. In that case as uniqueness is not guaranteed, heuristics are applied to determine the appropriate best match.

  • OGC URN combining references for compound coordinate reference systems (e.g “urn:ogc:def:crs,crs:EPSG::2393,crs:EPSG::5717” or custom abbreviated syntax “EPSG:2393+5717”),

  • OGC URN combining references for concatenated operations (e.g. “urn:ogc:def:coordinateOperation,coordinateOperation:EPSG::3895,coordinateOperation:EPSG::1618”)

  • PROJJSON string. The jsonschema is at proj.org/schemas/v0.4/projjson.schema.json (added in 6.2)

  • compound CRS made from two object names separated with “ + ”. e.g. “WGS 84 + EGM96 height” (added in 7.1)

Parameters:

  • value (String) —

    . See above

See Also:



54
55
56
57
58
59
60
61
62
63
64
65
66
67
 
# File 'lib/proj/conversion.rb', line 54

def initialize(value, context=nil)
  context ||= Context.current
  ptr = Api.proj_create(context, value)

  if ptr.null?
    Error.check_context(context)
  end

  if Api.method_defined?(:proj_is_crs) && Api.proj_is_crs(ptr)
    raise(Error, "Invalid conversion. Proj created an instance of: #{self.proj_type}.")
  end

  super(ptr, context)
end