HfBinary (arcpy.sa)

Récapitulatif

Defines the relationship between the horizontal cost factor and the horizontal relative moving angle through a binary function. If the horizontal relative moving angle is less than the cut angle, the horizontal factor is set to the value associated with the zero factor; otherwise it is infinity.

Illustration

HfBinary horizontal factor for the PathDistance functions.

Discussion

The HfBinary object is used in the Spatial Analyst tools: Path Distance, Path Distance Allocation, and Path Distance Back Link.

When the horizontal relative moving angle (HRMA) is less than the cut angle, the horizontal factor (HF) for moving through the section of the cell is set to the value associated with the zeroFactor. If the HRMA is greater than the cutAngle, the HF for the section is set to infinity.

Syntaxe

HfBinary ({zeroFactor}, {cutAngle})

Paramètre	Explication	Type de données
zeroFactor	The zeroFactor will be used to position the y-intercept of the binary function. (The zeroFactor is assigned as the horizontal factor when HRMA is less then the cutAngle.) (La valeur par défaut est 1.0)	Double
cutAngle	The cutAngle establishes the HRMA degree threshold beyond which the HFs are set to infinity. (When the HRMA is less than the cutAngle the horizontal factor is assigned to the zeroFactor; when the HRMA is greater than the cutAngle the horizontal factor is assigned infinity.) (La valeur par défaut est 45)	Double

Propriétés

Propriété	Explication	Type de données
zeroFactor (Lecture/écriture)	The zeroFactor will be used to position the y-intercept of the function. The zeroFactor is assigned as the horizontal factor when HRMA is less then the cut angle.	Double
cutAngle (Lecture/écriture)	The cutAngle establishes the HRMA degree threshold beyond which the HFs are set to infinity. When the HRMA is less than the cut angle then the zero factor is assigned and when the HRMA is greater than the cut angle, infinity is assigned.	Double

Exemple de code

HfBinary example 1 (Python window)

Demonstrates how to create a HFBinary class and use it in the PathDistance tool within the Python window.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
myHfBinary = HfBinary(1.5, 45.5)
outPathDist = PathDistance("source.shp", "elevation", "", "", myHfBinary)
outPathDist.save("C:/sapyexamples/output/pathdisthfb")

HfBinary example 2 (stand-alone script)

Performs a PathDistance analysis using the HFBinary class.

# Name: HfBinary_Ex_02.py
# Description: Uses the HFBinary object to execute the PathDistance tool.
# Requirements: Spatial Analyst Extension

# Import system modules
import arcpy
from arcpy import env
from arcpy.sa import *

# Set environment settings
env.workspace = "C:/sapyexamples/data"

# Set local variables
inSourceData = "sourcepts.shp"
inCostRaster = "elevation"

# Create the HfBinary Object
zeroFactor = 1.0
cutAngle = 45.0
myHorizFactor = HfBinary(zeroFactor, cutAngle)

# Check out the ArcGIS Spatial Analyst extension license
arcpy.CheckOutExtension("Spatial")

# Execute 
outPathDist = PathDistance(inSourceData, inCostRaster, "", "", myHorizFactor)

# Save the output 
outPathDist.save("C:/sapyexamples/output/pathdisthfb2")