VfCosSec
Zusammenfassung
Defines the relationship between the vertical cost factor and the vertical relative moving angle (VRMA) through a cosine/secant function. If the VRMA is negative the vertical factor is defined by a cosine function, and if the VRMA is nonnegative the vertical factor is defined by a secant function.
Abbildung
Beschreibung
The VfCosSec object is used in the Spatial Analyst tools Path Distance, Path Distance Allocation, and Path Distance Back Link.
The vertical factor (VF) object defines the relationship between the vertical cost factor and the vertical relative moving angle (VRMA).
VF defines the vertical difficulty encountered in moving from one cell to the next.
VRMA identifies the slope angle between the FROM or processing cell and the TO cell.
When the VRMA is a negative degree value, the VF is determined by the cosine function of the VRMA. If the VRMA is a positive degree value, the VF is determined by the secant function of the VRMA.
Syntax
Parameter | Erläuterung | Datentyp |
lowCutAngle |
The VRMA degree defining the lower threshold, below which (less than) the VFs are set to infinity. (Der Standardwert ist -90.0) | Double |
highCutAngle |
The VRMA degree defining the upper threshold, beyond which (larger than) the VFs are set to infinity. (Der Standardwert ist 90.0) | Double |
cosPower |
The power to which the values in the cosine VRMA function will be raised. The VF is determined by: VF = cos(VRMA)power (Der Standardwert ist 1.0) | Double |
secPower |
The power to which the values in the secant VRMA function will be raised. The VF is determined by: VF = sec(VRMA)power (Der Standardwert ist 1.0) | Double |
Eigenschaften
Eigenschaft | Erläuterung | Datentyp |
lowCutAngle (Lesen und schreiben) |
The VRMA degree defining the lower threshold, below which (less than) the VFs are set to infinity. | Double |
highCutAngle (Lesen und schreiben) |
The VRMA degree defining the upper threshold, beyond which (larger than) the VFs are set to infinity. | Double |
cosPower (Lesen und schreiben) |
The power to which the values in the cosine VRMA function will be raised. The VF is determined by: VF = cos(VRMA)power | Double |
secPower (Lesen und schreiben) |
The power to which the values in the secant VRMA function will be raised. The VF is determined by: VF = sec(VRMA)power | Double |
Codebeispiel
Demonstrates how to create a VfCosSec 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" myVerticalFactor = VfCosSec(-90, 90, 1, 1) outPathDist = PathDistance("source.shp", "costraster", "", "", "", "", myVerticalFactor) outPathDist.save("C:/sapyexamples/output/pathdistvsc")
Performs a PathDistance analysis using the VfCosSec class.
# Name: VfCosSec_Ex_02.py # Description: Uses the VfCosSec 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 = "source.shp" inCostRaster = "costraster" # Create the VfCosSec Object lowCutAngle = -90 highCutAngle = 90 cosPower = 1 secPower = 1 myVerticalFactor = VfCosSec(lowCutAngle, highCutAngle, cosPower, secPower) # Check out the ArcGIS Spatial Analyst extension license arcpy.CheckOutExtension("Spatial") # Execute PathDistance outPathDist = PathDistance(inSourceData, inCostRaster, "", "", "", "", myVerticalFactor) # Save the output outPathDist.save("C:/sapyexamples/output/pathdistvsc2")