LinearUnitConversionFactor

サマリー

Returns the factor for converting a distance measurement to a different linear unit.

説明

The linear units supported by the function are the same units returned from the geoprocessing Linear Units parameter data type, with the following exceptions:

  • Unknown—Only known units can be converted.
  • Decimal Degrees—Decimal degrees are measured on a sphere and do not have a consistent conversion factor to the other units.

Learn more about geoprocessing units of measurement

構文

LinearUnitConversionFactor (from_unit, to_unit)
パラメーター説明データ タイプ
from_unit

The original or source linear unit.

  • KilometersKilometers
  • MetersMeters
  • DecimetersDecimeters
  • MillimetersMillimeters
  • CentimetersCentimeters
  • NauticalMilesIntInternational nautical miles
  • MilesIntStatute miles
  • YardsIntInternational yards
  • FeetIntInternational feet
  • InchesIntInternational inches
  • NauticalMilesUSUS survey nautical miles
  • MilesUSUS survey miles
  • YardsUSUS survey yards
  • FeetUSUS survey feet
  • InchesUSUS survey inches
  • PointsPoints
String
to_unit

The target or destination linear unit.

  • KilometersKilometers
  • MetersMeters
  • DecimetersDecimeters
  • MillimetersMillimeters
  • CentimetersCentimeters
  • NauticalMilesIntInternational nautical miles
  • MilesIntStatute miles
  • YardsIntInternational yards
  • FeetIntInternational feet
  • InchesIntInternational inches
  • NauticalMilesUSUS survey nautical miles
  • MilesUSUS survey miles
  • YardsUSUS survey yards
  • FeetUSUS survey feet
  • InchesUSUS survey inches
  • PointsPoints
String
戻り値
データ タイプ説明
Double

The conversion factor for converting values between the two linear units.

コードのサンプル

LinearUnitConversionFactor example 1

A simple use case for converting from international miles to kilometers.

import arcpy

# Convert 620.5 MilesInt to Kilometers
620.5 * arcpy.LinearUnitConversionFactor(from_unit="MilesInt", to_unit="Kilometers")

print(area)  # This will print a value of 998.597952
LinearUnitConversionFactor example 2

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



import arcpy
import locale
import sys

dist = arcpy.GetParameter(n)  # Update n to the parameter index
dist_value, dist_unit = dist.split(" ")  # For example, "10 Kilometers"

# Convert the distance into "Meters" as needed later in this script
try:
    conv_factor = arcpy.LinearUnitConversionFactor(dist_unit, "Meters")
except ValueError as e:
    # If fails, the likely distance unit is "Unknown" or "Decimal Degrees".
    # Add code to either deal with it or produce an appropriate error as shown below.
    arcpy.AddError('Invalid linear 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
dist_m = locale.atof(dist_value) * conv_factor

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