Available in big data analytics.
The Aggregate Points tool can collect and summarize point features within area features. The boundaries from the area features are used to collect the points within each area and they are then used to calculate statistics. The resulting layer contains the count of points within each area as well as summary calculations.
Workflow diagram
Example
Tornadoes are a violent type of storm that occurs in the United States. You want to know the effect of tornadoes, including loss of life, injuries, property damage, and financial loss, in each state and county. You have access to tornado locations, but you need a better way to visualize the data within certain areas. You can aggregate your tornado data into state and county boundaries and normalize your data by population to find the areas most affected by tornadoes.
Usage notes
Keep the following in mind when working with the Aggregate Points tool:
- The output layer is always a polygon layer. Only the polygon bins or features where points occur are returned.
- You can provide the area layer to use for the analysis, or bins can be generated of a specified size and shape (hexagon or square), into which point features are aggregated. The bin size specifies how large the bins are. If you are aggregating into hexagons, the size is the height of each hexagon and the width of the resulting hexagon is two times the height divided by the square root of three. If you are aggregating into squares, the bin size is the height of the square, which is equal to the width.
- If time is enabled on your input layer, you may apply time stepping to your analysis.
- The most basic aggregations calculate a count of the number of points in each area. Statistics (Count, Sum, Min, Max, Range, Mean, Standard deviation, and Variance) can also be calculated on numerical fields and statistics (Count, Any) can be calculated on string fields. The statistics are calculated on each area separately.
- When Count is applied to a field, it returns a count of the nonnull values present in the field.
- When Any is applied to a string field, it returns a single string present in the field.
- The Aggregate Points tool allows you to optionally analyze using time steps. Each time step is analyzed independently of features outside of the time step. To use time stepping, your input data must be time enabled and represent an instant in time. When time stepping is applied, output features are time intervals represented by the StartTime and EndTime fields.
- If you specify a time-step interval, time-step repeat, or reference time, and time is not enabled on your data, the tool will result in an error.
- The Time Step Reference parameter can be a date and time value or solely a date value; it cannot be solely a time value.
Parameters
The following are the parameters for the Aggregate Points tool:
Parameter | Description | Data type |
---|---|---|
Input layer | The point features that are aggregated into bins or polygons. | Features |
Bin type | The bin shape that is used to create the regular bins. The choices are Square or Hexagon. If a polygon source is connected to the join port of this tool, this parameter does not appear or is required. | String |
Bin size | The distance interval that represents the bin size into which the input points are aggregated. For square bins, the bin size represents the height of a square. This is the default. For hexagonal bins, the bin size represents the height between two parallel sides. If a polygon source is connected to the join port of this tool, this parameter does not appear or is required. | String |
Interval (optional) | A value that specifies the duration of the time step. This option is only available if the input points are time enabled and represent an instant in time. Time stepping can only be applied if time is enabled on the input. | String |
Repeat (optional) | A value that specifies how often the time-step interval occurs. This option is only available if the input points are time enabled and represent an instant in time. | String |
Reference (optional) (optional) | A date that specifies the reference time with which to align the time steps. The default is January 1, 1970, at 12:00 a.m. This option is only available if the input points are time enabled and represent an instant in time. | Int64 |
Summary fields | The statistics that are calculated for specified fields. Different statistics are available depending on whether the specified field is a string, numeric, or date field.
| String |
Output layer
The output layer contains all original fields from the area features as well as the COUNT field. If you chose to configure summary fields, those fields would also be calculated for the output layer.
Field name | Description | Field type |
---|---|---|
COUNT | The number of point features from the input layer that were aggregated into this polygon feature. | Float64 |
Considerations and limitations
Lines and areas cannot be aggregated within boundaries using the Aggregate Points tool.