Euclidean Direction (Spatial Analyst)

Summary

Calculates, for each cell, the direction, in degrees, to the nearest source.

Learn more about Euclidean distance analysis

Illustration

Euclidean Direction illustration
Euc_Dir = EucDirection(Source_Ras)

Usage

Syntax

EucDirection (in_source_data, {maximum_distance}, {cell_size}, {out_distance_raster})
ParameterExplanationData Type
in_source_data

The input source locations.

This is a raster or feature dataset that identifies the cells or locations to which the Euclidean distance for every output cell location is calculated.

For rasters, the input type can be integer or floating point.

Raster Layer | Feature Layer
maximum_distance
(Optional)

Defines the threshold that the accumulative distance values cannot exceed.

If an accumulative Euclidean distance value exceeds this value, the output value for the cell location will be NoData.

The default distance is to the edge of the output raster.

Double
cell_size
(Optional)

The cell size at which the output raster will be created.

This will be the value in the environment if it is explicitly set. If it is not set in the environment, the default cell size will depend on if the input source data is a raster or a feature, as follows:

  • If the source is raster, the output will have that same cell size.
  • If the source is feature, the output will have a cell size determined by the shorter of the width or height of the extent of input feature, in the input spatial reference, divided by 250.

Analysis Cell Size
out_distance_raster
(Optional)

The output Euclidean distance raster.

The distance raster identifies, for each cell, the Euclidean distance to the closest source cell, set of source cells, or source location.

The output raster is of floating point type.

Raster Dataset

Return Value

NameExplanationData Type
out_direction_raster

The output Euclidean direction raster.

The direction raster contains the calculated direction, in degrees, each cell center is from the closest source cell center.

The range of values is from 0 degrees to 360 degrees, with 0 reserved for the source cells. Due east (right) is 90, and the values increase clockwise (180 is south, 270 is west, and 360 is north).

The output raster is of integer type.

Raster

Code Sample

EucDirection example 1 (Python window)

The following Python Window script demonstrates how to use the EuclideanDirection tool.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
outEucDirect = EucDirection("observers", 35000, 50, 
                            "c:/sapyexamples/output/optoutdist")
outEucDirect.save("c:/sapyexamples/output/eucoutdir")
EucDirection example 2 (stand-alone script)

Calculates the direction in degrees that each cell center is from the cell center of the closest source.

# Name: EucDirection_Ex_02.py
# Description: Calculates the direction in degrees that each 
#              cell center is from the cell center of the 
#              closest source.
# Requirements: Spatial Analyst Extension
# Author: ESRI

# Import system modules
import arcpy
from arcpy import env
from arcpy.sa import *

# Set environment settings
env.workspace = "C:/sapyexamples/data"

# Set local variables
inSource = "observers.shp"
maxDist = 35000
cellSize = 50
optOutDistance = "c:/sapyexamples/output/optdistout"

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

# Execute EucDirections
outEucDirect = EucDirection(inSource, maxDist, cellSize, 
                            optOutDistance)

# Save the output 
outEucDirect.save("c:/sapyexamples/output/eucoutdir02")

Environments

Related Topics

Licensing Information

ArcView: Requires Spatial Analyst
ArcEditor: Requires Spatial Analyst
ArcInfo: Requires Spatial Analyst

6/29/2011