方向分布 (标准差椭圆) (空间统计)

许可等级:BasicStandardAdvanced

摘要

创建标准差椭圆以概括地理要素的空间特征:中心趋势、离散和方向趋势。

了解“方向分布”(标准差椭圆)的工作原理

插图

Directional Distribution (Standard Deviational Ellipse) graphic

用法

语法

DirectionalDistribution_stats (Input_Feature_Class, Output_Ellipse_Feature_Class, Ellipse_Size, {Weight_Field}, {Case_Field})
参数说明数据类型
Input_Feature_Class

要计算标准差椭圆的要素分布所在的要素类。

Feature Layer
Output_Ellipse_Feature_Class

包含输出椭圆要素的面要素类。

Feature Class
Ellipse_Size

标准差中输出椭圆的大小。默认椭圆大小为 1;可供选择的选项为 1、2 或 3 标准差。

  • 1_STANDARD_DEVIATION
  • 2_STANDARD_DEVIATIONS
  • 3_STANDARD_DEVIATIONS
String
Weight_Field
(可选)

根据各位置的相对重要性对它们进行加权的数值型字段。

Field
Case_Field
(可选)

对要素进行分组以分别计算方向分布的字段。案例分组字段可以为整型、日期型或字符串型。

Field

代码实例

DirectionalDistribution 示例(Python 窗口)

下面的 Python 窗口脚本演示了如何使用 DirectionalDistribution 工具。

import arcpy
arcpy.env.workspace = r"C:\data"
arcpy.DirectionalDistribution_stats("AutoTheft.shp", "auto_theft_SE.shp", "1_STANDARD_DEVIATION", "#", "#")
DirectionalDistribution 示例(独立 Python 脚本)

下面的独立 Python 脚本演示了如何使用 DirectionalDistribution 工具。

# Measure the geographic distribution of auto thefts
 
# Import system modules
import arcpy
 
# Local variables...
workspace = "C:/data"
locations = "AutoTheft.shp"
links = "AutoTheft_links.shp"
standardDistance = "auto_theft_SD.shp"
stardardEllipse = "auto_theft_SE.shp"
linearDirectMean = "auto_theft_LDM.shp"
 
try:
    # Set the workspace (to avoid having to type in the full path to the data every time)
    arcpy.env.workspace = workspace
 
    # Process: Standard Distance of auto theft locations...
    arcpy.StandardDistance_stats(locations, standardDistance, "1_STANDARD_DEVIATION", "#", "#")
 
    # Process: Directional Distribution (Standard Deviational Ellipse) of auto theft locations...
    arcpy.DirectionalDistribution_stats(locations, standardEllipse, "1_STANDARD_DEVIATION", "#", "#")
 
    # Process: Linear Directional Mean of auto thefts...
    arcpy.DirectionalMean_stats(links, linearDirectMean, "DIRECTION", "#")
 
except:
    # If an error occurred while running a tool, print the messages 
    print arcpy.GetMessages()

环境

输出坐标系

在进行分析之前将要素几何投影到输出坐标系。所有数学计算都基于输出坐标系空间参考

相关主题

许可信息

ArcGIS for Desktop Basic: 是
ArcGIS for Desktop Standard: 是
ArcGIS for Desktop Advanced: 是
5/10/2014