# VfSecCos (arcpy.sa)

## 插图

 路径垂直功能的 VfSecCos 垂直系数。

## 讨论

VfSecCos 对象用于 Spatial Analyst 工具路径距离路径距离分配路径距离回溯链接

VF 用于定义从一个像元移至下一像元的垂直阻力。

VRMA 用于确定“起始”像元或处理像元与“终止”像元之间的坡度角。

## 语法

VfSecCos ({lowCutAngle}, {highCutAngle}, {secPower}, {cosPower})
 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 secPower The power to which the values in the secant VRMA function will be raised. The VF is determined by: ` VF = sec(VRMA)power` (默认值为 1.0) 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(读写) The VRMA degree defining the lower threshold, below which (less than) the VFs are set to infinity. Double highCutAngle(读写) The VRMA degree defining the upper threshold, beyond which (larger than) the VFs are set to infinity. Double secPower(读写) The power to which the values in the secant VRMA function will be raised. The VF is determined by: ` VF = sec(VRMA)power` Double cosPower(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

## 代码实例

VfSecCos 示例 1（Python 窗口）

``````import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
myVerticalFactor = VfSecCos(-90, 90, 1, 1)
outPathDist = PathDistance("source.shp", "costraster", "", "", "", "",
myVerticalFactor)
outPathDist.save("C:/sapyexamples/output/pathdistvfsc")
``````
VfSecCos 示例 2（独立脚本）

``````# Name: VfSecCos_Ex_02.py
# Description: Uses the VfSecCos 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 VfSecCos Object
lowCutAngle = -90
highCutAngle = 90
secPower = 1
cosPower = 1
myVerticalFactor = VfSecCos(lowCutAngle, highCutAngle, secPower, 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/pathdistvfsc2")
``````

5/10/2014