ArealUnitConversionFactor

サマリー

Returns the factor for converting an area measurement to a different areal unit.

説明

The area units supported by the function are the same units returned from the geoprocessing Area Units parameter data type with the exception of Unknown, in which only known units can be converted.

Learn more about geoprocessing units of measurement

構文

ArealUnitConversionFactor (from_unit, to_unit)

パラメーター	説明	データ タイプ
from_unit	The original or source areal unit. SquareKilometers—Square kilometers Hectares—Hectares Ares—Ares SquareMeters—Square meters SquareDecimeters—Square decimeters SquareCentimeters—Square centimeters SquareMillimeters—Square millimeters SquareMilesInt—Square statute miles AcresInt—International acres SquareYardsInt—Square international yards SquareFeetInt—Square international feet SquareInchesInt—Square international inches SquareMilesUS—Square US survey miles AcresUS—Square US survey acres SquareYardsUS—Square US survey yards SquareFeetUS—Square US survey feet SquareInchesUS—Square US survey inches	String
to_unit	The destination areal unit. SquareKilometers—Square kilometers Hectares—Hectares Ares—Ares SquareMeters—Square meters SquareDecimeters—Square decimeters SquareCentimeters—Square centimeters SquareMillimeters—Square millimeters SquareMilesInt—Square statute miles AcresInt—International acres SquareYardsInt—Square international yards SquareFeetInt—Square international feet SquareInchesInt—Square international inches SquareMilesUS—Square US survey miles AcresUS—Square US survey acres SquareYardsUS—Square US survey yards SquareFeetUS—Square US survey feet SquareInchesUS—Square US survey inches	String

戻り値

データ タイプ	説明
Double	The conversion factor for converting values between the two areal units.

コードのサンプル

ArealUnitConversionFactor example 1

A simple use case for converting from hectare to square kilometers.

import arcpy

# Convert an area of 10000 Hectares to SquareKilometers 
area = 10000 * arcpy.ArealUnitConversionFactor(from_unit="Hectares", to_unit="SquareKilometers")

print(area)  # This will print a value of 100.0

ArealUnitConversionFactor example 2

Within a script tool, convert a specified value to square meters for processing.

import locale
import sys

area = arcpy.GetParameter(n)  # Update n to the parameter index

area_value, area_unit = area.split(" ")  # For example, "10 Acres"

# Convert the area into "SquareMeters" as needed later in this script
try:
    conv_factor = arcpy.ArealUnitConversionFactor(area_unit, "SquareMeters")
except ValueError as e:
    # If fails, the likely area; unit is "Unknown"
    # Add code to either deal with it or produce an appropriateerror  as shown below.
    arcpy.AddError(arcpy.GetIDMessage('Invalid areal unit type.))
    sys.exit()

# Apply the conv_factor to the supplied value
# locale.atof is required for locales that don't use a period as the separator
area_square_m = locale.atof(area_value) * conv_factor