VfCos
摘要
Defines the relationship between the vertical cost factor and the vertical relative moving angle through a cosine function.
插图
讨论
The VfCos 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 VF is determined by the cosine function of the VRMA.
语法
参数 | 说明 | 数据类型 |
lowCutAngle |
The VRMA degree defining the lower threshold, below which (less than) the VFs are set to infinity. (默认值为 -90.0) | Double |
highCutAngle |
The VRMA degree defining the upper threshold, beyond which (larger than) the VFs are set to infinity. (默认值为 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 (默认值为 1.0) | Double |
属性
属性 | 说明 | 数据类型 |
lowCutAngle (可读写) |
The VRMA degree defining the lower threshold, below which (less than) the VFs are set to infinity. | Double |
highCutAngle (可读写) |
The VRMA degree defining the upper threshold, beyond which (larger than) the VFs are set to infinity. | Double |
cosPower (可读写) |
The power to which the values in the cosine VRMA function will be raised. The VF is determined by: VF = cos(VRMA)power | Double |
代码示例
Demonstrates how to create a VfCos 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 = VfCos(-15, 15, 1.5) outPathDist = PathDistance("source.shp", "costraster", "", "", "", "", myVerticalFactor) outPathDist.save("C:/sapyexamples/output/pathdistvfc")
Performs a PathDistance analysis using the VfCos class.
# Name: VfCos_Ex_02.py # Description: Uses the VfCos 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 VfCos Object lowCutAngle = -15 highCutAngle = 45 cosPower = 2 myVerticalFactor = VfCos(lowCutAngle, highCutAngle, cosPower) # 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/pathdistvfc2")