NbrAnnulus
サマリ
Defines an annulus neighborhood which is created by specifying an inner and outer circles' radii in either map units or number of cells.
図
説明
Tools that use neighborhood annulus object: Block Statistics, Focal Statistics, Point Statistics, and Point Density.
The annulus shape is comprised of two circles, one inside the other to make a donut shape. Cells with centers that fall outside the radius of the smaller circle but inside the radius of the larger circle will be included in processing the neighborhood; therefore, the area that falls between the two circles constitutes the annulus neighborhood.
When the annulus object is used and the innerRadius or the outerRadius are not specified, then default values are provided.
The innerRadius must be less than or equal to the outerRadius.
The radius is identified in cells or map units, measured perpendicular to the x- or y-axis. When the radii is specified in map units, they are converted to radii in cell units. The resulting radii in cell units produces an area that most closely represents the area calculated by using the original radii in map units. Any cell center encompassed by the annulus will be included in the processing of the neighborhood.
構文
パラメータ | 説明 | データ タイプ |
innerRadius |
The inner radius of an annulus neighborhood. (デフォルト値は 1) | Double |
outerRadius |
The outer radius of an annulus neighborhood. (デフォルト値は 3) | Double |
units |
Defines the units of the neighborhood.
(デフォルト値は CELL) | String |
プロパティ
プロパティ | 説明 | データ タイプ |
innerRadius (読み書き) |
The inner radius of the annulus neighborhood. | Double |
outerRadius (読み書き) |
The outer radius of the annulus neighborhood. | Double |
units (読み書き) |
Defines the units of the neighborhood. | String |
コードのサンプル
Demonstrates how to create a NbrAnnulus class and use it in the BlockStatistics tool within the Python window.
import arcpy from arcpy import env from arcpy.sa import * env.workspace = "C:/sapyexamples/data" outNbrA = BlockStatistics("block", NbrAnnulus(1, 2, "CELL")) outNbrA.save("C:/sapyexamples/output/blstatnbra2")
Implements the BlockStatistics tool using the NbrAnnulus class.
# Name: NbrAnnulus_Ex_02.py # Description: Uses the NbrAnnulus object to execute BlockStatistics 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 inRaster = "block" # Create the Neighborhood Object innerRadius = 1 outerRadius = 3 myNbrAnnulus = NbrAnnulus(innerRadius, outerRadius, "MAP") # Check out the ArcGIS Spatial Analyst extension license arcpy.CheckOutExtension("Spatial") # Execute BlockStatistics outBlkStats = BlockStatistics(inRaster, myNbrAnnulus, "MINIMUM", "DATA") # Save the output outBlkStats.save("C:/sapyexamples/output/blstat_Ann3")