Aggregate Points (Standard Feature Analysis)

Summary

Uses a layer of point features and a layer of polygon features to identify the points that fall within each polygon's area. After identifying the point-in-polygon spatial relationship, statistics about all points in the polygon are calculated and assigned to the area.

The most basic statistic is the count of the number of points within the polygon, but you can get other statistics as well. For example, if the points represent coffee shops and each point has a TOTAL_SALES attribute, you can get statistics such as the sum of all TOTAL_SALES values within the polygon, or the minimum or maximum TOTAL_SALES value, or the standard deviation of all sales within the polygon.

Illustration

Usage

• This tool collects and summarizes point features within a set of boundaries. The input parameters must include points to be aggregated, as well as aggregation areas.

• The Keep boundaries with no points parameter is checked by default. When the parameter is checked, all of the areas used in the analysis will be included in the result, regardless of the location of the points. Areas with no points will be empty and have a count of 0. When the parameter is unchecked, the areas with no points are removed from the result layer. Unchecking this parameter may have a significant effect on the result areas.

  

  The difference in result layers when boundaries with no points are kept (first image) or not kept (second image) is shown.

• The most basic aggregations will calculate a count of the number of points in each boundary. Basic statistics (sum, minimum, maximum, average, and standard deviation) can also be calculated on numerical fields. The statistics will be calculated on each area separately.

• Statistical calculations can also be grouped using a field with categorical values. When statistics are grouped by a field, the statistics are calculated for both the area as a whole and for each group. Both statistics can be viewed in the result layer's pop-up. The overall statistics are provided numerically, and the grouped statistics are shown in chart form in the pop-up. A summary table listing each feature and statistic by group field value will also be created. Checking the Add minority and majority attributes parameter will return the groups with the lowest and highest counts, and checking the Add percentage parameter will return the percentage of points in the minority and majority groups.

• Point layers are summarized using only the point features within the input boundary. The results will be displayed using graduated symbols.

  The figure and table below explain the statistical calculations of a point layer within a hypothetical boundary. The Population field was used to calculate the statistics (Sum, Minimum, Maximum, Average, and Std Deviation) for the layer.

  

  Point layers are summarized using only points located within the boundary layer. An example attribute table with values to be used in hypothetical statistic calculations is shown.

  Statistic	Results District A
  Sum	280 + 408 + 356 + 361 + 450 + 713 = 2,568
  Minimum	Minimum of [280, 408, 356, 361, 450, 713] = 280
  Maximum	Maximum of [280, 408, 356, 361, 450, 713] = 713
  Average	2,568/6 = 428
  Std Deviation	= 150.79

Parameters

Dialog

Label	Explanation	Data Type
Input Points	The point features that will be aggregated into the polygons in the polygon layer.	Feature Set
Aggregating Polygons	The polygon features (areas) into which the input points will be aggregated.	Feature Set
Output Name	The name of the output layer that will be created on your portal.	String
Keep boundaries with no points (Optional)	Specifies whether the polygons that have no points within them will be returned in the output. Checked—Polygons that have no points will be returned in the output. This is the default. Unchecked—Polygons that have no points will not be returned in the output.	Boolean
Summary Fields (Optional)	A list of field names and statistical summary type that will be calculated for all points within each polygon. The count of points within each polygon is always returned. The following statistic types are supported: Sum—The total value Minimum—The smallest value Max—The largest value Mean—The average or mean value Standard deviation—The standard deviation	Value Table
Group By Field (Optional)	A field name in the pointLayer. Points that have the same value for the group by field will have their own counts and summary field statistics. You can create statistical groups using an attribute in the analysis layer. For example, if you are aggregating crimes to 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 value of Crime_type. When you choose a grouping attribute, two results are created: the result layer and a related table containing the statistics.	Field
Add minority and majority attributes (Optional)	Specifies whether minority and majority fields will be added to the output. This parameter is applicable only when a Group By Field value is provided. If checked, the minority (least dominant) or the majority (most dominant) attribute values for each group field within each boundary will be calculated. Two new fields will be added to the output layer prefixed with Majority_ and Minority_. Unchecked—Minority and majority fields will not be added. This is the default. Checked—Minority and majority fields will be added.	Boolean
Add percentage (Optional)	Specifies whether percentage fields will be added to the output. This parameter is applicable only when a Group By Field value is provided. If checked, the percentage count of points for each unique Group By Field value will be calculated. A new field will be added to the output group summary table containing the percentages of each attribute value in each group. If Add minority and majority attributes is checked, two more fields will be added to the output containing the percentages of the minority and majority attribute values in each group. Unchecked—Percentage fields will not be added. This is the default. Checked—Percentage fields will be added.	Boolean

Derived Output

Label	Explanation	Data Type
Output Layer	The output layer.	Feature Set
Output Group Layer	The output table that summarizes the groups from the Group By Field.	Record Set

Python

arcpy.sfa.AggregatePoints(pointLayer, polygonLayer, outputName, {keepBoundariesWithNoPoints}, {summaryFields}, {groupByField}, {minorityMajority}, {percentPoints})

Name	Explanation	Data Type
pointLayer	The point features that will be aggregated into the polygons in the polygon layer.	Feature Set
polygonLayer	The polygon features (areas) into which the input points will be aggregated.	Feature Set
outputName	The name of the output layer that will be created on your portal.	String
keepBoundariesWithNoPoints (Optional)	Specifies whether the polygons that have no points within them will be returned in the output. KEEP_EMPTY—Polygons that have no points will be returned in the output. This is the default. REMOVE_EMPTY—Polygons that have no points will not be returned in the output.	Boolean
summaryFields [[Field, Statistic],...] (Optional)	A list of field names and statistical summary type that will be calculated for all points within each polygon. The count of points within each polygon is always returned. The following statistic types are supported: SUM—The total value MIN—The smallest value MAX—The largest value MEAN—The average or mean value STD—The standard deviation	Value Table
groupByField (Optional)	A field name in the pointLayer. Points that have the same value for the group by field will have their own counts and summary field statistics. You can create statistical groups using an attribute in the analysis layer. For example, if you are aggregating crimes to 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 value of Crime_type. When you choose a grouping attribute, two results are created: the result layer and a related table containing the statistics.	Field
minorityMajority (Optional)	Specifies whether minority and majority fields will be added. This parameter is applicable only when a groupByField value is provided. If set to ADD_MIN_MAJ, the minority (least dominant) or the majority (most dominant) attribute values for each group field within each boundary will be calculated. Two new fields will be added to the output layer prefixed with Majority_ and Minority_. NO_MIN_MAJ—Minority and majority fields will not be added. This is the default. ADD_MIN_MAJ—Minority and majority fields will be added.	Boolean
percentPoints (Optional)	Specifies whether percentage fields will be added to the output. This parameter is applicable only when a groupByField value is provided. If set to ADD_PERCENT, the percentage count of points for each unique groupByField value will be calculated. A new field will be added to the output group summary table containing the percentages of each attribute value in each group. If minorityMajority is set to ADD_MIN_MAJ, two more fields will be added to the output containing the percentages of the minority and majority attribute values in each group. NO_PERCENT—Do not add percentage fields. This is the default. ADD_PERCENT—Add percentage fields.	Boolean

Derived Output

Name	Explanation	Data Type
aggregatedLayer	The output layer.	Feature Set
groupSummary	The output table that summarizes the groups from the Group By Field.	Record Set

Environments

Output Coordinate System, Extent, Current Workspace

Licensing information

• Basic: Requires your account in ArcGIS Enterprise to have the Perform Analysis privilege
• Standard: Requires your account in ArcGIS Enterprise to have the Perform Analysis privilege
• Advanced: Requires your account in ArcGIS Enterprise to have the Perform Analysis privilege