Disponible con una licencia de Spatial Analyst.
Resumen
Defines the relationship between the vertical cost factor and the vertical relative moving angle through a linear function.
Ilustración
Debate
The VfLinear 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.
The VFs are determined by a straight line in the VRMA-VF coordinate system. The line intercepts the y-axis, equitable to the VF factor, at the value associated with the zeroFactor. The slope of the line can be specified using the slope argument.
Sintaxis
VfLinear ({zeroFactor}, {lowCutAngle}, {highCutAngle}, {slope})| Parámetro | Explicación | Tipo de datos |
zeroFactor | The zeroFactor will be used to position the y-intercept of the linear function. (El valor predeterminado es 1.0) | Double |
lowCutAngle | The VRMA degree defining the lower threshold, below which (less than) the VFs are set to infinity. (El valor predeterminado es -90.0) | Double |
highCutAngle | The VRMA degree defining the upper threshold, beyond which (larger than) the VFs are set to infinity. (El valor predeterminado es 90.0) | Double |
slope | Identifies the slope of the straight line in the VRMA-VF coordinate system. Slope is specified as the rise/run. For example, a 30-degree slope is 1/30, specified as 0.03333 (rise/run: 1 VF on the y axis / 30 degrees on the x axis); a 90-degree slope as 0.011111. (El valor predeterminado es 0.011111) | Double |
Propiedades
| Propiedad | Explicación | Tipo de datos |
| zeroFactor (Lectura y escritura) | The zeroFactor is used to position the y-intercept for the vertical factor class. | Double |
| lowCutAngle (Lectura y escritura) | The VRMA degree defining the lower threshold, below which (less than) the VFs are set to infinity. | Double |
| highCutAngle (Lectura y escritura) | The VRMA degree defining the upper threshold, beyond which (larger than) the VFs are set to infinity. | Double |
| slope (Lectura y escritura) | Identifies the slope of the straight line in the VRMA-VF coordinate system. Slope is specified as the rise over the run. For example, a 30-degree slope is 1/30, specified as 0.03333 (rise/run: 1 VF on the y axis / 30 degrees on the x axis); a 90-degree slope as 0.011111. | Double |
Ejemplo de código
VfLinear example 1 (Python window)
Demonstrates how to create a VfLinear 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 = VfLinear(1.0, -90.0, 90.0, 0.01111)
outPathDist = PathDistance("source.shp", "costraster", "", "", "", "",
myVerticalFactor)
outPathDist.save("C:/sapyexamples/output/pastdistvfl")
VfLinear example 2 (stand-alone script)
Performs a PathDistance analysis using the VfLinear class.
# Name: VfLinear_Ex_02.py
# Description: Uses the VfLinear 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 VfLinear Object
zeroFactor = 1.0
lowCutAngle = -90
highCutAngle = 90
slope = 0.01111
myVerticalFactor = VfLinear(zeroFactor, lowCutAngle, highCutAngle, slope)
# 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/pastdistvfl2")