SpatialReference (arcpy)

Resumen

Each part of the spatial reference has a number of properties (especially the coordinate system) that defines what map projection options are used to define horizontal coordinates.

Debate

A SpatialReference object can also be accessed from existing datasets using the Describe spatialReference property.

dataset = "c:/data/landbase.gdb/Wetlands"
spatial_ref = arcpy.Describe(dataset).spatialReference

Nota:

Which spatial reference properties are available depends on the coordinate system used. In the properties list below, those properties only available with a Projected Coordinate system are denoted with a ¹; properties available only with a Geographic Coordinate system are denoted with a ².

Sintaxis

SpatialReference ({item})

Parámetro	Explicación	Tipo de datos
item	The spatial reference can be created in three ways: Using the name of the coordinate system sr = arcpy.SpatialReference("Hawaii Albers Equal Area Conic") Using a projection file (.prj) sr = arcpy.SpatialReference("c:/coordsystems/NAD 1983.prj") Using a coordinate system's factory code (or authority code) # 32145 is the code for: # NAD 1983 StatePlane Vermont FIPS 4400 (Meters) sr = arcpy.SpatialReference(32145) For more information on coordinate system names and factory codes, see geographic_coordinate_systems.pdf and projected_coordinate_systems.pdf files in the ArcGIS Documentation folder. For more information, see Using the spatial reference class.	String

Propiedades

Propiedad	Explicación	Tipo de datos
GCS (Sólo lectura)	If a projected coordinate system, returns a SpatialReference object for the geographic coordinate system it is based on. If a geographic coordinate system, returns the same SpatialReference.	SpatialReference
MDomain (Sólo lectura)	The extent of the measure domain.	String
MFalseOriginAndUnits (Sólo lectura)	The measure false origin and units.	String
MResolution (Lectura y escritura)	The measure resolution.	Double
MTolerance (Lectura y escritura)	The measure tolerance.	Double
XYResolution (Lectura y escritura)	The xy resolution.	Double
XYTolerance (Lectura y escritura)	The xy tolerance.	Double
ZDomain (Sólo lectura)	The extent of the Z domain.	String
ZFalseOriginAndUnits (Sólo lectura)	The Z false origin and units.	String
ZResolution (Lectura y escritura)	The Z resolution property.	Double
ZTolerance (Lectura y escritura)	The Z tolerance property.	Double
abbreviation (Lectura y escritura)	The abbreviated name of the spatial reference.	String
alias (Lectura y escritura)	The alias of the spatial reference.	String
domain (Sólo lectura)	The extent of the xy domain.	String
factoryCode (Lectura y escritura)	The factory code of the spatial reference.	Integer
falseOriginAndUnits (Sólo lectura)	The false origin and units.	String
hasMPrecision (Sólo lectura)	Indicates whether or not m-value precision information has been defined.	Boolean
hasXYPrecision (Sólo lectura)	Indicates whether or not xy precision information has been defined.	Boolean
hasZPrecision (Sólo lectura)	Indicates whether or not z-value precision information has been defined.	Boolean
isHighPrecision (Lectura y escritura)	Indicates whether or not the spatial reference has high precision set.	Boolean
name (Lectura y escritura)	The name of the spatial reference.	String
remarks (Lectura y escritura)	The comment string of the spatial reference.	String
type (Lectura y escritura)	The type of the spatial reference.	String
usage (Sólo lectura)	The usage notes.	String
PCSCode (Lectura y escritura)	The projected coordinate system code.^1	Integer
PCSName (Lectura y escritura)	The projected coordinate system name.^1	String
azimuth (Lectura y escritura)	The azimuth of a projected coordinate system.^1	Double
centralMeridian (Lectura y escritura)	The central meridian of a projected coordinate system.^1	Double
centralMeridianInDegrees (Lectura y escritura)	The central meridian (Lambda0) of a projected coordinate system in degrees.^1	Double
centralParallel (Lectura y escritura)	The central parallel of a projected coordinate system.^1	Double
classification (Sólo lectura)	The classification of a map projection.^1	String
falseEasting (Lectura y escritura)	The false easting of a projected coordinate system.^1	Double
falseNorthing (Lectura y escritura)	The false northing of a projected coordinate system.^1	Double
latitudeOf1st (Lectura y escritura)	The latitude of the first point of a projected coordinate system.^1	Double
latitudeOf2nd (Lectura y escritura)	The latitude of the second point of a projected coordinate system.^1	Double
linearUnitCode (Lectura y escritura)	The linear unit code.^1	Integer
linearUnitName (Lectura y escritura)	The linear unit name.^1	String
longitude (Lectura y escritura)	The longitude value of this prime meridian.^1	Double
longitudeOf1st (Lectura y escritura)	The longitude of the first point of a projected coordinate system.^1	Double
longitudeOf2nd (Lectura y escritura)	The longitude of the second point of a projected coordinate system.^1	Double
longitudeOfOrigin (Lectura y escritura)	The longitude of origin of a projected coordinate system.^1	Double
metersPerUnit (Sólo lectura)	The meters per linear unit.^1	Double
projectionCode (Lectura y escritura)	The projection code.^1	Integer
projectionName (Lectura y escritura)	The projection name.^1	String
scaleFactor (Lectura y escritura)	The scale factor of a projected coordinate system.^1	Double
standardParallel1 (Lectura y escritura)	The first parallel of a projected coordinate system.^1	Double
standardParallel2 (Lectura y escritura)	The second parallel of a projected coordinate system.^1	Double
GCSCode (Lectura y escritura)	The geographic coordinate system code.^2	Integer
GCSName (Lectura y escritura)	The geographic coordinate system name.^2	String
angularUnitCode (Lectura y escritura)	The angular unit code.^2	Integer
angularUnitName (Lectura y escritura)	The angular unit name.^2	String
datumCode (Lectura y escritura)	The datum code.^2	Integer
datumName (Lectura y escritura)	The datum name.^2	String
flattening (Lectura y escritura)	The flattening ratio of this spheroid.^2	Double
longitude (Lectura y escritura)	The longitude value of this prime meridian.^2	Double
primeMeridianCode (Lectura y escritura)	The prime meridian code.^2	Integer
primeMeridianName (Lectura y escritura)	The prime meridian name.^2	String
radiansPerUnit (Sólo lectura)	The radians per angular unit.^2	Double
semiMajorAxis (Lectura y escritura)	The semi-major axis length of this spheroid.^2	Double
semiMinorAxis (Lectura y escritura)	The semi-minor axis length of this spheroid.^2	Double
spheroidCode (Lectura y escritura)	The spheroid code.^2	Integer
spheroidName (Lectura y escritura)	The spheroid name.^2	String

Descripción general de los métodos

Método	Explicación
create ()	Creates the spatial reference object using properties.
createFromFile (prj_file)	Creates the spatial reference object from a projection file.
exportToString ()	Exports the object to its string representation.
loadFromString (string)	Restore the object using its string representation. The exportToString method can be used to create a string representation.
setDomain (x_min, x_max, y_min, y_max)	Sets the XY domain.
setFalseOriginAndUnits (false_x, false_y, xy_units)	Sets the XY false origin and units.
setMDomain (m_min, m_max)	Sets the M domain.
setMFalseOriginAndUnits (false_m, m_units)	Sets the M false origin and units.
setZDomain (z_min, z_max)	Sets the Z domain.
setZFalseOriginAndUnits (false_z, z_units)	Sets the Z false origin and units.

Métodos

create ()

createFromFile (prj_file)

Parámetro	Explicación	Tipo de datos
prj_file	The projection file used to populate the spatial reference object.	String

exportToString ()

Valor de retorno

Tipo de datos	Explicación
String	The string representation of the object.

loadFromString (string)

Parámetro	Explicación	Tipo de datos
string	The string representation of the object.	String

setDomain (x_min, x_max, y_min, y_max)

Parámetro	Explicación	Tipo de datos
x_min	The minimum x-value.	Double
x_max	The maximum x-value.	Double
y_min	The minimum y-value.	Double
y_max	The maximum y-value.	Double

setFalseOriginAndUnits (false_x, false_y, xy_units)

Parámetro	Explicación	Tipo de datos
false_x	The false x value.	Double
false_y	The false y value.	Double
xy_units	The xy units.	String

setMDomain (m_min, m_max)

Parámetro	Explicación	Tipo de datos
m_min	The minimum m-value.	Double
m_max	The maximum m-value.	Double

setMFalseOriginAndUnits (false_m, m_units)

Parámetro	Explicación	Tipo de datos
false_m	The false m-value.	Double
m_units	The m units.	Double

setZDomain (z_min, z_max)

Parámetro	Explicación	Tipo de datos
z_min	The minimum z-value.	Double
z_max	The maximum z-value.	Double

setZFalseOriginAndUnits (false_z, z_units)

Parámetro	Explicación	Tipo de datos
false_z	The false z-value.	Double
z_units	The false z units.	Double

Ejemplo de código

SpatialReference example

For each feature class in a workspace, print the name of its spatial reference.

import arcpy

# Set the workspace environment
arcpy.env.workspace = "c:/base/base.gdb"

# Get a list of the feature classes in the input folder
feature_classes = arcpy.ListFeatureClasses()

# Loop through the list
for fc in feature_classes:
    # Create the spatial reference object
    spatial_ref = arcpy.Describe(fc).spatialReference

    # If the spatial reference is unknown
    if spatial_ref.name == "Unknown":
        print("{0} has an unknown spatial reference".format(fc))

    # Otherwise, print out the feature class name and
    # spatial reference
    else:
        print("{0} : {1}".format(fc, spatial_ref.name))