Euclidean Distance

Calculates, for each cell, the Euclidean distance to the closest source.

Usage tips

Command line and Scripting

• The input source data can be a feature class or raster.

• When the input source data is a raster, the set of source cells consists of all cells in the source raster that have valid values. It must be an integer raster. Cells that have NoData values are not included in the source set. The value zero is considered a legitimate source. A source raster can be easily created using the Extract By tools.

• When the input source data is a feature class, the source locations are converted internally to a raster before performing the Euclidean analysis. The resolution of the raster can be controlled with the Output cell size parameter.

• The Euclidean functions are calculated from non-source cells assigned NoData.

• The maximum distance is specified in the same map units as the input source data.

• The output distance raster is of floating point type.

• The output direction raster is of integer type.

• Allocation is not an available output because there can be no floating-point information in the source data. If allocation output is desired, use Euclidean Allocation, which can generate all three outputs (allocation, distance, and direction) at the same time.

• If a mask has been set in the environment and the cells to be masked will mask a source, the Euclidean calculations will occur on the remaining source cells. The source cells that are masked will not be considered in the computations. These cell locations will be assigned NoData on the output rasters.

• The NoData values created by the masked cells are ignored in the Euclidean function calculations on non-source cell locations. The Euclidean distance for cells behind NoData values is calculated as if the NoData value is not present. Any cell location that is assigned NoData because of the mask on the input surface will receive NoData on all the output rasters (Euclidean Distance and, optionally, Euclidean Direction).

• The following environment settings affect this tool:

Syntax

EucDistance_sa (in_source_data, out_distance_raster, maximum_distance, cell_size, out_direction_raster)
Parameter Explanation Datatype
Input raster or feature source data (Required)

The input source locations.

A raster or feature dataset that identifies the cells or locations to which the Euclidean distance for every cell location is calculated. If raster, it must be integer type.

Distance is calculated only to the single closest source cell or location.

Composite Geodataset
Output distance raster (Required)

The name of 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.

Raster Dataset
Maximum distance (Optional)

Defines the threshold that the accumulative distance values cannot exceed.

If an accumulative Euclidean distance value exceeds the {maximum_distance}, the output value for the cell location will be NoData. The {maximum_distance} defines the extent for which the accumulative Euclidean distances are calculated. The default distance is to the edge of the output raster.

Double
Output 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's not set in the environment, and if the in_source_data is a raster, the cell size will default to that of the in_source_data. If the in_source_data is a feature dataset, the cell size will default to the shorter of the width or height of the extent of input features in the input spatial reference, divided by 250.

Analysis cell size
Output direction raster (Optional)

The name of 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 0 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).

Raster Dataset
Data types for geoprocessing tool parameters

Script Example

```# EucDistance_sample.py
# Description:
#   Calculates for each cell the Euclidean distance to the nearest source.
# Requirements: None
# Author: ESRI
# Date: Sept 6, 2005

# Import system modules
import arcgisscripting

# Create the Geoprocessor object
gp = arcgisscripting.create()

try:
# Set local variables
InSourceData = "C:/data/source.shp"
OutDistanceRaster = "C:/data/dist_ras"
InMaxDistance = "2"
InCellSize = "30"
OutDirectionRaster = "C:/data/dir_ras"

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

# Process: EucDistance
gp.EucDistance_sa(InSourceData, OutDistanceRaster, InMaxDistance, InCellSize, OutDirectionRaster)

except:
# If an error occurred while running a tool, then print the messages.
print gp.GetMessages()

```

See EucDistance