SpatialReference (arcpy)

Récapitulatif

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.

Discussion

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

dataset = "C:/Data/Landbase.gdb/Wetlands"
spatialRef = arcpy.Describe(dataset).spatialReference
RemarqueRemarque :

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.

Syntaxe

SpatialReference ({item})
ParamètreExplicationType de données
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

Propriétés

PropriétéExplicationType de données
GCS
(Lecture seule)

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
(Lecture seule)

The extent of the measure domain.

String
MFalseOriginAndUnits
(Lecture seule)

The measure false origin and units.

String
MResolution
(Lecture/écriture)

The measure resolution.

Double
MTolerance
(Lecture/écriture)

The measure tolerance.

Double
XYResolution
(Lecture/écriture)

The xy resolution.

Double
XYTolerance
(Lecture/écriture)

The xy tolerance.

Double
ZDomain
(Lecture seule)

The extent of the Z domain.

String
ZFalseOriginAndUnits
(Lecture seule)

The Z false origin and units.

String
ZResolution
(Lecture/écriture)

The Z resolution property.

Double
ZTolerance
(Lecture/écriture)

The Z tolerance property.

Double
abbreviation
(Lecture/écriture)

The abbreviated name of the spatial reference.

String
alias
(Lecture/écriture)

The alias of the spatial reference.

String
domain
(Lecture seule)

The extent of the xy domain.

String
factoryCode
(Lecture/écriture)

The factory code of the spatial reference.

Integer
falseOriginAndUnits
(Lecture seule)

The false origin and units.

String
hasMPrecision
(Lecture seule)

Indicates whether or not m-value precision information has been defined.

Boolean
hasXYPrecision
(Lecture seule)

Indicates whether or not xy precision information has been defined.

Boolean
hasZPrecision
(Lecture seule)

Indicates whether or not z-value precision information has been defined.

Boolean
isHighPrecision
(Lecture/écriture)

Indicates whether or not the spatial reference has high precision set.

Boolean
name
(Lecture/écriture)

The name of the spatial reference.

String
remarks
(Lecture/écriture)

The comment string of the spatial reference.

String
type
(Lecture/écriture)

The type of the spatial reference.

String
usage
(Lecture seule)

The usage notes.

String
PCSCode
(Lecture/écriture)

The projected coordinate system code.1

Integer
PCSName
(Lecture/écriture)

The projected coordinate system name.1

String
azimuth
(Lecture/écriture)

The azimuth of a projected coordinate system.1

Double
centralMeridian
(Lecture/écriture)

The central meridian of a projected coordinate system.1

Double
centralMeridianInDegrees
(Lecture/écriture)

The central meridian (Lambda0) of a projected coordinate system in degrees.1

Double
centralParallel
(Lecture/écriture)

The central parallel of a projected coordinate system.1

Double
classification
(Lecture seule)

The classification of a map projection.1

String
falseEasting
(Lecture/écriture)

The false easting of a projected coordinate system.1

Double
falseNorthing
(Lecture/écriture)

The false northing of a projected coordinate system.1

Double
latitudeOf1st
(Lecture/écriture)

The latitude of the first point of a projected coordinate system.1

Double
latitudeOf2nd
(Lecture/écriture)

The latitude of the second point of a projected coordinate system.1

Double
linearUnitCode
(Lecture/écriture)

The linear unit code.1

Integer
linearUnitName
(Lecture/écriture)

The linear unit name.1

String
longitude
(Lecture/écriture)

The longitude value of this prime meridian.1

Double
longitudeOf1st
(Lecture/écriture)

The longitude of the first point of a projected coordinate system.1

Double
longitudeOf2nd
(Lecture/écriture)

The longitude of the second point of a projected coordinate system.1

Double
longitudeOfOrigin
(Lecture/écriture)

The longitude of origin of a projected coordinate system.1

Double
projectionCode
(Lecture/écriture)

The projection code.1

Integer
projectionName
(Lecture/écriture)

The projection name.1

String
scaleFactor
(Lecture/écriture)

The scale factor of a projected coordinate system.1

Double
standardParallel1
(Lecture/écriture)

The first parallel of a projected coordinate system.1

Double
standardParallel2
(Lecture/écriture)

The second parallel of a projected coordinate system.1

Double
GCSCode
(Lecture/écriture)

Code du système de coordonnées géographiques.2

Integer
GCSName
(Lecture/écriture)

Nom du système de coordonnées géographiques.2

String
angularUnitCode
(Lecture/écriture)

Code d'unité angulaire.2

Integer
angularUnitName
(Lecture/écriture)

Nom d'unité angulaire.2

String
datumCode
(Lecture/écriture)

Code du datum.2

Integer
datumName
(Lecture/écriture)

Nom du datum.2

String
flattening
(Lecture/écriture)

Coefficient d'aplatissement de cette sphéroïde.2

Double
longitude
(Lecture/écriture)

Valeur de longitude de ce méridien principal.2

Double
primeMeridianCode
(Lecture/écriture)

Code de méridien principal.2

Integer
primeMeridianName
(Lecture/écriture)

Nom du méridien principal.2

String
radiansPerUnit
(Lecture seule)

Radians par unité angulaire.2

Double
semiMajorAxis
(Lecture/écriture)

Longueur du demi-grand axe de ce sphéroïde.2

Double
semiMinorAxis
(Lecture/écriture)

Longueur du demi-petit axe de ce sphéroïde.2

Double
spheroidCode
(Lecture/écriture)

Code du sphéroïde.2

Integer
spheroidName
(Lecture/écriture)

Nom du sphéroïde.2

String

Vue d'ensemble des méthodes

MéthodeExplication
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.

Méthodes

create ()
createFromFile (prj_file)
ParamètreExplicationType de données
prj_file

The projection file used to populate the spatial reference object.

String
exportToString ()
Valeur renvoyée
Type de donnéesExplication
String

The string representation of the object.

loadFromString (string)
ParamètreExplicationType de données
string

The string representation of the object.

String
setDomain (x_min, x_max, y_min, y_max)
ParamètreExplicationType de données
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)
ParamètreExplicationType de données
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)
ParamètreExplicationType de données
m_min

The minimum m-value.

Double
m_max

The maximum m-value.

Double
setMFalseOriginAndUnits (false_m, m_units)
ParamètreExplicationType de données
false_m

The false m-value.

Double
m_units

The m units.

Double
setZDomain (z_min, z_max)
ParamètreExplicationType de données
z_min

The minimum z-value.

Double
z_max

The maximum z-value.

Double
setZFalseOriginAndUnits (false_z, z_units)
ParamètreExplicationType de données
false_z

The false z-value.

Double
z_units

The false z units.

Double

Exemple de code

SpatialReference example

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

import arcpy
from arcpy import env

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

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

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

    # If the spatial reference is unknown
    #
    if sr.name == "Unknown":
        print fc + " has an unknown spatial reference\n"

    # Otherwise, print out the feature class name and
    #   spatial reference
    #
    else:
        print fc + ": " + sr.name + "\n"

Thèmes connexes

Utilisation de classes dans Python
Utilisation de la classe de références spatiales
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9/12/2013