SpatialReference (arcpy)
摘要
空间参考的每一部分都具有多个属性,特别是坐标系,它定义了哪些地图投影选项用于定义水平坐标。
讨论
也可使用 Describe spatialReference 属性从现有数据集访问 SpatialReference 对象。
dataset = "C:/Data/Landbase.gdb/Wetlands"
spatialRef = arcpy.Describe(dataset).spatialReference
注:空间参考属性的可用性取决于所使用的坐标系。在下面的属性列表中,只可用于投影坐标系的属性以 1 表示;只可用于地理坐标系的属性以 2 表示。
语法
| 参数 | 说明 | 数据类型 | 
item  | 
 The spatial reference can be created in three ways: 
 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 | 
属性
| 属性 | 说明 | 数据类型 | 
| GCS (只读)  | 
 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 (只读)  | 
 The extent of the measure domain.  | String | 
| MFalseOriginAndUnits (只读)  | 
 The measure false origin and units.  | String | 
| MResolution (读写)  | 
 The measure resolution.  | Double | 
| MTolerance (读写)  | 
 The measure tolerance.  | Double | 
| XYResolution (读写)  | 
 The xy resolution.  | Double | 
| XYTolerance (读写)  | 
 The xy tolerance.  | Double | 
| ZDomain (只读)  | 
 The extent of the Z domain.  | String | 
| ZFalseOriginAndUnits (只读)  | 
 The Z false origin and units.  | String | 
| ZResolution (读写)  | 
 The Z resolution property.  | Double | 
| ZTolerance (读写)  | 
 The Z tolerance property.  | Double | 
| abbreviation (读写)  | 
 The abbreviated name of the spatial reference.  | String | 
| alias (读写)  | 
 The alias of the spatial reference.  | String | 
| domain (只读)  | 
 The extent of the xy domain.  | String | 
| factoryCode (读写)  | 
 The factory code of the spatial reference.  | Integer | 
| falseOriginAndUnits (只读)  | 
 The false origin and units.  | String | 
| hasMPrecision (只读)  | 
 Indicates whether or not m-value precision information has been defined.  | Boolean | 
| hasXYPrecision (只读)  | 
 Indicates whether or not xy precision information has been defined.  | Boolean | 
| hasZPrecision (只读)  | 
 Indicates whether or not z-value precision information has been defined.  | Boolean | 
| isHighPrecision (读写)  | 
 Indicates whether or not the spatial reference has high precision set.  | Boolean | 
| name (读写)  | 
 The name of the spatial reference.  | String | 
| remarks (读写)  | 
 The comment string of the spatial reference.  | String | 
| type (读写)  | 
 The type of the spatial reference.  | String | 
| usage (只读)  | 
 The usage notes.  | String | 
| PCSCode (读写)  | 
 The projected coordinate system code.1  | Integer | 
| PCSName (读写)  | 
 The projected coordinate system name.1  | String | 
| azimuth (读写)  | 
 The azimuth of a projected coordinate system.1  | Double | 
| centralMeridian (读写)  | 
 The central meridian of a projected coordinate system.1  | Double | 
| centralMeridianInDegrees (读写)  | 
 The central meridian (Lambda0) of a projected coordinate system in degrees.1  | Double | 
| centralParallel (读写)  | 
 The central parallel of a projected coordinate system.1  | Double | 
| classification (只读)  | 
 The classification of a map projection.1  | String | 
| falseEasting (读写)  | 
 The false easting of a projected coordinate system.1  | Double | 
| falseNorthing (读写)  | 
 The false northing of a projected coordinate system.1  | Double | 
| latitudeOf1st (读写)  | 
 The latitude of the first point of a projected coordinate system.1  | Double | 
| latitudeOf2nd (读写)  | 
 The latitude of the second point of a projected coordinate system.1  | Double | 
| linearUnitCode (读写)  | 
 The linear unit code.1  | Integer | 
| linearUnitName (读写)  | 
 The linear unit name.1  | String | 
| longitude (读写)  | The longitude value of this prime meridian.1  | Double | 
| longitudeOf1st (读写)  | 
 The longitude of the first point of a projected coordinate system.1  | Double | 
| longitudeOf2nd (读写)  | 
 The longitude of the second point of a projected coordinate system.1  | Double | 
| longitudeOfOrigin (读写)  | 
 The longitude of origin of a projected coordinate system.1  | Double | 
| projectionCode (读写)  | 
 The projection code.1  | Integer | 
| projectionName (读写)  | 
 The projection name.1  | String | 
| scaleFactor (读写)  | 
 The scale factor of a projected coordinate system.1  | Double | 
| standardParallel1 (读写)  | 
 The first parallel of a projected coordinate system.1  | Double | 
| standardParallel2 (读写)  | 
 The second parallel of a projected coordinate system.1  | Double | 
| GCSCode (读写)  | 
 The geographic coordinate system code.2  | Integer | 
| GCSName (读写)  | 
 The geographic coordinate system name.2  | String | 
| angularUnitCode (读写)  | 
 The angular unit code.2  | Integer | 
| angularUnitName (读写)  | 
 The angular unit name.2  | String | 
| datumCode (读写)  | 
 The datum code.2  | Integer | 
| datumName (读写)  | 
 The datum name.2  | String | 
| flattening (读写)  | 
 The flattening ratio of this spheroid.2  | Double | 
| longitude (读写)  | 
 The longitude value of this prime meridian.2  | Double | 
| primeMeridianCode (读写)  | 
 The prime meridian code.2  | Integer | 
| primeMeridianName (读写)  | 
 The prime meridian name.2  | String | 
| radiansPerUnit (只读)  | 
 The radians per angular unit.2  | Double | 
| semiMajorAxis (读写)  | 
 The semi-major axis length of this spheroid.2  | Double | 
| semiMinorAxis (读写)  | 
 The semi-minor axis length of this spheroid.2  | Double | 
| spheroidCode (读写)  | 
 The spheroid code.2  | Integer | 
| spheroidName (读写)  | 
 The spheroid name.2  | String | 
方法概述
| 方法 | 说明 | 
| 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) | 
 设置 XY 属性域。  | 
| 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) | 
 设置 M 的假定原点和单位。  | 
| setZDomain (z_min, z_max) | 
 Sets the Z domain.  | 
| setZFalseOriginAndUnits (false_z, z_units) | 
 设置 Z 的假定原点和单位。  | 
方法
| 参数 | 说明 | 数据类型 | 
prj_file  | 
 The projection file used to populate the spatial reference object.  | String | 
| 数据类型 | 说明 | 
| String | 
 The string representation of the object.  | 
| 参数 | 说明 | 数据类型 | 
string  | 
 The string representation of the object.  | String | 
| 参数 | 说明 | 数据类型 | 
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 | 
| 参数 | 说明 | 数据类型 | 
false_x  | 
 The false x value.  | Double | 
false_y  | 
 The false y value.  | Double | 
xy_units  | 
 The xy units.  | String | 
| 参数 | 说明 | 数据类型 | 
m_min  | 
 The minimum m-value.  | Double | 
m_max  | 
 The maximum m-value.  | Double | 
| 参数 | 说明 | 数据类型 | 
false_m  | 
 The false m-value.  | Double | 
m_units  | 
 The m units.  | Double | 
| 参数 | 说明 | 数据类型 | 
z_min  | 
 The minimum z-value.  | Double | 
z_max  | 
 The maximum z-value.  | Double | 
| 参数 | 说明 | 数据类型 | 
false_z  | 
 The false z-value.  | Double | 
z_units  | 
 The false z units.  | Double | 
代码实例
对工作空间中的每个要素类,输出其空间参考的名称。
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"