NbrCircle (arcpy.sa)

Zusammenfassung

Defines a circle neighborhood which is created by specifying the radius in either map units or number of cells.

Bild

NbrCircle neighborhood example for the FocalStatistics function

NbrCircle neighborhood example for the BlockStatistics function

Diskussion

Tools that use neighborhood circle object: Block Statistics, Focal Statistics, Point Statistics, and Point Density.

A circle neighborhood is created by specifying a radius value. The radius is identified in cell or map units, measured perpendicular to the x- or y-axis. When the radius is specified in map units, it is converted to a radius in cell units. The resulting radius in cell units produces an area that most closely represents the area calculated by using the original radius in map units. Any cell center encompassed by the circle will be included in the processing of the neighborhood.

Syntax

NbrCircle ({radius}, {units})

Parameter	Erläuterung	Datentyp
radius	The radius of the circle neighborhood. (Der Standardwert ist 3)	Double
units	Defines the units of the neighborhood. CELL —The unit of measurement is in cells. MAP —The units are in map coordinates. (Der Standardwert ist CELL)	String

Eigenschaften

Eigenschaft	Erläuterung	Datentyp
radius (Lesen und schreiben)	The radius of the circle neighborhood.	Double
units (Lesen und schreiben)	Defines the units of the neighborhood.	String

Codebeispiel

NbrCircle example 1 (Python window)

Demonstrates how to create a NbrCircle 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"
outNbrC = BlockStatistics("block", NbrCircle(2, "MAP"))
outNbrC.save("C:/sapyexamples/output/blstatsnbrc2")

NbrCircle example 2 (stand-alone script)

Implements the BlockStatistics tool using the NbrCircle class.

# Name: NbrCircle_Ex_02.py
# Description: Uses the NbrCircle 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
radius = 2
myNbrCirc = NbrCircle(radius, "MAP")

# Check out the ArcGIS Spatial Analyst extension license
arcpy.CheckOutExtension("Spatial")

# Execute BlockStatistics
outBlkStat =  BlockStatistics(inRaster, myNbrCirc, "MINIMUM", "DATA")

# Save the output 
outBlkStat.save("C:/sapyexamples/output/blstat_cir3")