Line Statistics

Available with Spatial Analyst license.

Summary

Calculates a statistic on the attributes of lines in a circular neighborhood around each output cell.

Learn more about how Line Statistics works

Usage

• Only the part of a line within the neighborhood is considered for the Majority, Mean, Median, Minority, and Length statistics. For the others, it does not matter whether a part or the whole line is used.

• If there are no lines in the neighborhood of a raster cell, then the Variety and Length statistics assign a value of zero. For the other statistics, NoData is assigned.

• The statistic types Majority, Mean, Median, and Minority are weighted according to the length of the lines. For example, if a line is twice as long as another, its value is considered to occur twice as often.

• The values on the output raster will always be integer in the case of Variety. They will always be floating point for Mean and Length. For the other statistics, the output data type is the same as the input item value type.

• For statistic types Majority, Maximum, Median, Minimum, Minority, and Range, the output data type of the raster will be the same as the input field type. For statistics types Mean and Length, the output raster will always be floating point. For Variety, the output raster will always be integer.

• See Analysis environments and Spatial Analyst for additional details on the geoprocessing environments that apply to this tool.

Syntax

LineStatistics (in_polyline_features, field, {cell_size}, {search_radius}, {statistics_type})

Parameter	Explanation	Data Type
in_polyline_features	The input polyline features for which to calculate the statistics in a neighbourhood around each output cell.	Feature Layer
field	The field that the specified statistic will be calculated for. It can be any numeric field of the input features. When the statistics type is set to LENGTH, the Field can be set to None. It can be the Shape field if the input features contain z.	Field
cell_size (Optional)	Cell size for output raster dataset. This is the value in the environment if specifically set. If not set in the environment, it is the shorter of the width or height of the extent of the input feature dataset, in the output spatial reference, divided by 250.	Analysis Cell Size
search_radius (Optional)	Search radius to calculate the desired statistic within, in map units. The default radius is five times the output cell size.	Double
statistics_type (Optional)	The statistic type to be calculated. Statistics are calculated on the value of the specified field for all lines within the neighborhood. MEAN — Calculates the average field value in each neighborhood, weighted by the length.The form of the calculation is: Mean = (sum of (length * field_value)) / (sum_of_length) Only the part of the length that falls within the neighborhood is used. MAJORITY — Determines the value having the greatest length of line in the neighborhood. MAXIMUM —Determines the largest value in the neighborhood. MEDIAN — Determines the median value, weighted by the length.Conceptually, all line segments in the neighborhood are sorted by value and placed end-to-end in a straight line. The value of the segment at the midpoint of the straight line is the median. MINIMUM — Calculates smallest value in each neighborhood. MINORITY — The value having the least length of line in the neighborhood. RANGE — The range of values (maximum–minimum). VARIETY — The number of unique values. LENGTH —The total line length in the neighborhood. If the value of the field is other than 1, the lengths are multiplied by the item value before adding them together. This option can be used when the Field is set to None. When the specified field is integer, the available statistic choices are Mean, Majority, Maximum, Median, Minimum, Minority, Range, and Variety. When the field is floating point, the only allowed statistics are Mean, Maximum, Minimum, and Range.	String

Return Value

Name	Explanation	Data Type
out_raster	The output line statistics raster.	Raster

Code Sample

LineStatistics example 1 (Python window)

This example calculates the average length of line segments within a certain radius of each cell in the input raster.

import arcpy
from arcpy import env
from arcpy.sa import *
env.workspace = "C:/sapyexamples/data"
lineStatOut = LineStatistics("streams", "LENGTH", 50, 500, "MEAN")
lineStatOut.save("C:/sapyexamples/output/linestatout")

LineStatistics example 2 (stand-alone script)

This example calculates the average length of line segments within a certain radius of each cell in the input raster.

# Name: LineStatistics_Ex_02.py
# Description: 
# 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
inLines = "streams.shp"
field = "LENGTH"
cellSize = 50
searchRadius = 500

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

# Execute LineStatistics
lineStatOut = LineStatistics(inLines, field, cellSize, searchRadius,
                              "MEAN")

# Save the output 
lineStatOut.save("C:/sapyexamples/output/linestatisout")

Environments

• Auto Commit
• Cell Size
• Compression
• Current Workspace
• Extent
• Geographic Transformations
• Output CONFIG Keyword
• Output Coordinate System
• Raster Statistics
• Scratch Workspace
• Snap Raster
• Tile Size

Licensing Information

• ArcGIS for Desktop Basic: Requires Spatial Analyst
• ArcGIS for Desktop Standard: Requires Spatial Analyst
• ArcGIS for Desktop Advanced: Requires Spatial Analyst

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