The Calculate Density tool creates a density map (polygon) from point or line features by spreading known quantities of a phenomenon (represented as attributes of the points or lines) across the map.
Learn more about how Kernel Density works
Examples
Uses include analyzing density of housing or occurrences of crime for community planning purposes and exploring how roads or utility lines influence wildlife habitat.
Usage notes
Calculate Density includes configurations for input layers, analysis settings, and the result layer.
Input layers
The Input layers group includes the following parameters:
Input point or line features is the input point or line layer that will be used to calculate density. For feature inputs, a count of features is displayed below the layer name. The count includes all features in the layer, except features that have been removed using a filter. Environment settings, such as Processing extent, are not reflected in the feature count.
Population field specifies the number of incidents at each location. The field type is numerical.
If the default value of None is used, each location will be assumed to represent a single count.
Clip output to defines the area where densities will be calculated. You can choose a layer using the Layer button, or use the Draw input features button to create a sketch layer to use as the input. For feature inputs, a count of features is displayed below the layer name. The count includes all features in the layer, except features that have been removed using a filter. Environment settings, such as Processing extent, are not reflected in the feature count.
Density analysis settings
The Density analysis settings group includes the following parameters:
Search distance and units is the distance that will be searched to find point or line features when calculating density values.
The available units are feet, international feet, international yards, miles, statute miles, meters, and kilometers.
Classify by specifies how density values will be classified into areas. The options are as follows:
- Equal interval—Areas will be created so that the range of density values is equal for each area.
- Geometric interval—Areas will be based on class intervals that have a geometrical series. This method ensures that each class range has approximately the same number of values in each class and that the change between intervals is consistent.
- Natural breaks—Class intervals for areas will be based on natural groupings of the data. Class break values that best group similar values and that maximize the differences between classes will be identified.
- Equal area—Areas will be created so that the size of each area is equal. For example, if the result layer has more high density values than low density values, additional areas will be created for high densities.
- Standard deviation—Areas will be created based on the standard deviation of the predicted density values.
Number of classes is the number of classes (range of predicted values) in the result layer. The minimum value is 3, the maximum value is 32, and the default value is 10.
Area units is the output area unit. Density is count divided by area, and this parameter specifies the unit of the area in the density calculation. The available areal units are square miles, square feet, square meters, and square kilometers.
Result layer
The Result layer group includes the following parameters:
Output polygon name is the name of the output density feature layer that will be created.
The name must be unique. If a layer with the same name already exists in your organization, the tool will fail and you will be prompted to use a different name.
- Save in folder specifies the name of a folder in My content where the result will be saved.
Environments
Analysis environment settings are additional parameters that affect a tool's results. You can access the tool's analysis environment settings from the Environment settings parameter group.
This tool honors the following analysis environments:
- Output coordinate system
- Processing extent
Note:
The default processing extent is Full extent. This default is different from Map Viewer Classic in which Use current map extent is enabled by default.
Outputs
The output is a polygon feature layer of kernel density. The value is related to the selected population field value.
Usage requirements
This tool requires the following user type and configurations:
- Creator, Professional, or Professional Plus user type
- Publisher or Administrator role, or an equivalent custom role
- ArcGIS Server Advanced
Resources
Use the following resources to learn more:
- How Calculate Density works
- Calculate Density in ArcGIS REST API
- calculate_density in ArcGIS API for Python
- Calculate Density in ArcGIS Pro with the Raster Analysis extension
- Kernel Density in ArcGIS Pro with the Spatial Analyst extension