Summarize Within (Analysis)

Summary

Overlays a polygon layer with another layer to summarize the number of points, length of the lines, or area of the polygons within each polygon, and calculate attribute field statistics about the features within the polygons.

The following are example scenarios using Summarize Within:

• If you have a layer of watershed boundaries and a layer of land-use boundaries by land-use type, you can calculate total acreage of land-use type for each watershed.
• If you have a layer of parcels in a county and a layer of city boundaries, you can summarize the average value of vacant parcels within each city boundary.
• If you have a layer of counties and a layer of roads, you can summarize the total mileage of roads by road type in each county.

Illustration

Usage

• Think of Summarize Within as taking two layers, the input polygons and the input summary features, and stacking them on top of each other. After stacking these layers, you can look down through the stack and count the number of input summary features that fall within the input polygons. You can also calculate simple statistics about the attributes of the input summary features, such as sum, mean, minimum, maximum, and so on.

• The Summarize Within and Summarize Nearby tools are conceptually similar. Using the Summarize Within tool, you can summarize features within existing polygons. Using the Summarize Nearby tool, you can generate areas around points, lines, or polygons, and summarize features within those derived areas.

• You can create groups by specifying a group field from the input points. For example, if you are summarizing crimes within neighborhood boundaries, you may have a Crime_type attribute with five crime types. Each unique crime type forms a group, and the statistics you choose will be calculated for each unique Crime_type value.

• Null values are excluded from all statistical calculations. For example, the average of 10, 5, and a null value is 7.5 ((10+5)/2).

Parameters

Dialog

Label	Explanation	Data Type
Input Polygons	The polygons used to summarize the features, or portions of features, in the input summary layer.	Feature Layer
Input Summary Features	The point, line, or polygon features that will be summarized for each polygon in the input polygons.	Feature Layer
Output Feature Class	The output polygon feature class containing the same geometries and attributes as the input polygons with additional new attributes for the number of points, length of lines, and area of polygons inside each input polygon and statistics about those features.	Feature Class
Keep all input polygons (Optional)	Specifies whether all input polygons or only those intersecting or containing at least one input summary feature will be copied to the output feature class. Checked—All input polygons will be copied to the output feature class. This is the default. Unchecked—Only input polygons that intersect or contain at least one input summary feature will be copied to the output feature class.	Boolean
Summary Fields (Optional)	A list of attribute field names from the input summary features, as well as statistical summary types that will be calculated for those attribute fields for all points in each polygon. Summary fields must be numeric. Text and other attribute field types are not supported. The following are the statistic types: Sum—The total value of all the points in each polygon will be calculated. Mean—The average of all the points in each polygon will be calculated. Min—The smallest value of all the points in each polygon will be identified. Max—The largest value of all the points in each polygon will be identified. Stddev—The standard deviation of all the points in each polygon will be calculated.	Value Table
Add shape summary attributes (Optional)	Specifies whether attributes for the number of points, length of lines, and area of polygon features summarized in each input polygon will be added to the output feature class. Checked—Shape summary attributes will be added to the output feature class. This is the default. Unchecked—Shape summary attributes will not be added to the output feature class.	Boolean
Shape Unit (Optional)	Specifies the unit that will be used when calculating shape summary attributes. If the input summary features are points, no shape unit is necessary, since only the count of points in each input polygon is added. If the input summary features are lines, specify a linear unit. If the input summary features are polygons, specify an areal unit. Meters—The unit will be meters. Kilometers—The unit will be kilometers. Feet—The unit will be feet. Yards—The unit will be yards. Miles—The unit will be miles. Acres—The unit will be acres. Hectares—The unit will be hectares. Square meters—The unit will be square meters. Square kilometers—The unit will be square kilometers. Square feet—The unit will be square feet. Square yards—The unit will be square yards. Square miles—The unit will be square miles.	String
Group Field (Optional)	An attribute field from the input summary features that is used for grouping. Features that have the same group field value will be combined and summarized with other features with the same group field value. When a group field is specified, the Output Grouped Table parameter is required.	Field
Add minority and majority attributes (Optional)	Specifies whether minority and majority fields will be added to the output. This parameter allows you to determine which group field value is the minority (least dominant) and the majority (most dominant) within each input polygon. This parameter is active if you specified a Group Field parameter value. Unchecked—Minority and majority fields will not be added to the output. This is the default. Checked—Minority and majority fields will be added to the output.	Boolean
Add group percentages (Optional)	Specifies whether a percentage attribute field will be added to the output. This parameter allows you to determine the percentage of each attribute value in each group. This parameter is active if you specified a Group Field parameter value. Unchecked—A percentage attribute field will not be added to the output. This is the default. Checked—A percentage attribute field will be added to the output.	Boolean
Output Grouped Table (Optional)	An output table that includes summary fields for each group of summary features for each input polygon. The table will have the following attribute fields: Join_ID—An ID corresponding to an ID field added to the output feature class The group field A shape summary field One field for each summary field Percentage field This parameter is required when the Group Field parameter value is specified.	Table

Python

arcpy.analysis.SummarizeWithin(in_polygons, in_sum_features, out_feature_class, {keep_all_polygons}, {sum_fields}, {sum_shape}, {shape_unit}, {group_field}, {add_min_maj}, {add_group_percent}, {out_group_table})

Name	Explanation	Data Type
in_polygons	The polygons used to summarize the features, or portions of features, in the input summary layer.	Feature Layer
in_sum_features	The point, line, or polygon features that will be summarized for each polygon in the input polygons.	Feature Layer
out_feature_class	The output polygon feature class containing the same geometries and attributes as the input polygons with additional new attributes for the number of points, length of lines, and area of polygons inside each input polygon and statistics about those features.	Feature Class
keep_all_polygons (Optional)	Specifies whether all input polygons or only those containing at least one input summary feature will be copied to the output feature class. KEEP_ALL—All input polygons will be copied to the output feature class. This is the default. ONLY_INTERSECTING—Only input polygons that intersect or contain at least one input summary feature will be copied to the output feature class.	Boolean
sum_fields [[summary_field, statistic_type],...] (Optional)	A list of attribute field names from the input summary features, as well as statistical summary types that will be calculated for those attribute fields for all points in each polygon. Summary fields must be numeric. Text and other attribute field types are not supported. The following are the statistic types: Sum—The total value of all the points in each polygon will be calculated. Mean—The average of all the points in each polygon will be calculated. Min—The smallest value of all the points in each polygon will be identified. Max—The largest value of all the points in each polygon will be identified. Stddev—The standard deviation of all the points in each polygon will be calculated.	Value Table
sum_shape (Optional)	Specifies whether attributes for the number of points, length of lines, and area of polygon features summarized in each input polygon will be added to the output feature class. ADD_SHAPE_SUM—Shape summary attributes will be added to the output feature class. This is the default. NO_SHAPE_SUM—Shape summary attributes will not be added to the output feature class.	Boolean
shape_unit (Optional)	Specifies the unit that will be used when calculating shape summary attributes. If the input summary features are points, no shape unit is necessary, since only the count of points in each input polygon is added. If the input summary features are lines, specify a linear unit. If the input summary features are polygons, specify an areal unit. METERS—The unit will be meters. KILOMETERS—The unit will be kilometers. FEET—The unit will be feet. YARDS—The unit will be yards. MILES—The unit will be miles. ACRES—The unit will be acres. HECTARES—The unit will be hectares. SQUAREMETERS—The unit will be square meters. SQUAREKILOMETERS—The unit will be square kilometers. SQUAREFEET—The unit will be square feet. SQUAREYARDS—The unit will be square yards. SQUAREMILES—The unit will be square miles.	String
group_field (Optional)	An attribute field from the input summary features that is used for grouping. Features that have the same group field value will be combined and summarized with other features with the same group field value. When a group field is specified, the out_grouped_table parameter is required.	Field
add_min_maj (Optional)	Specifies whether minority and majority fields will be added to the output. This parameter allows you to determine which group field value is the minority (least dominant) and the majority (most dominant) within each input polygon. This parameter is enabled if you specified a group_field parameter value. NO_MIN_MAJ—Minority and majority fields will not be added to the output. This is the default. ADD_MIN_MAJ—Minority and majority fields will be added to the output.	Boolean
add_group_percent (Optional)	Specifies whether a percentage attribute field will be added to the output. This parameter allows you to determine the percentage of each attribute value in each group. This parameter is enabled if you specified a group_field parameter value. NO_PERCENT—A percentage attribute field will not be added to the output. This is the default. ADD_PERCENT—A percentage attribute field will be added to the output.	Boolean
out_group_table (Optional)	An output table that includes summary fields for each group of summary features for each input polygon. The table will have the following attribute fields: Join_ID—An ID corresponding to an ID field added to the output feature class The group field A shape summary field One field for each summary field Percentage field This parameter is required when the group_field parameter value is specified.	Table

Code sample

SummarizeWithin example 1 (Python window)

The following Python window script demonstrates how to use the SummarizeWithin function.

import arcpy
arcpy.env.workspace = 'C:/data/city.gdb'
arcpy.analysis.SummarizeWithin('neighborhoods', 'crimes', 'neighborhood_crimes')

SummarizeWithin example 2 (stand-alone script)

The following stand-alone script is an example of how to use the SummarizeWithin function in a scripting environment.

# Description: Use SummarizeWithin to summarize the crimes in each city neighborhood

# import system modules 
import arcpy

# Set environment settings
arcpy.env.workspace = 'C:/data/city.gdb'

#  Set local variables
polys = 'neighborhoods'
points = 'crimes'
outFeatureClass = 'crimes_aggregated'
keepAll = 'KEEP_ALL'
sumFields = [['Damages', 'SUM'], ['VICTIM_AGE', 'MEAN']]
addShapeSum = 'ADD_SHAPE_SUM'
groupField = 'Crime_type'
addMinMaj = 'ADD_MIN_MAJ'
addPercents = 'ADD_PERCENT'
outTable = 'crimes_aggregated_groups'

arcpy.analysis.SummarizeWithin(polys, points, outFeatureClass, keepAll, 
                               sumFields, addShapeSum, '', groupField, 
                               addMinMaj, addPercents, outTable)

Environments

Output Coordinate System, Extent, Current Workspace, Scratch Workspace, Output has Z values, Z Resolution, Default Output Z Value, Geographic Transformations, Output XY Domain, Output Z Domain, XY Resolution, XY Tolerance, Z Tolerance

Licensing information

• Basic: Yes
• Standard: Yes
• Advanced: Yes