Find Hot Spots (Grids)

Overview

The Find Hot Spots tool generates a grid of equal-sized cells based on your defined extents. You can create grid cells based on the current extent, study area extent, or extent of a feature in another layer. You can append demographic data to a grid cell to provide a normalized view of the data, identifying hot spots and areas of interest. The hot spot grid areas appear with prominent red coloring by default.

Input Prerequisites

This is a defined extent.

Example Output

This example shows a typical Grid analysis output created in Business Analyst:

• A default thematic layer is added to the map symbolized from the variable you choose.
• The attribute table contains unique cell identifiers and aggregated data for each selected variable for every cell.
• By default, the variable is divided into five classes using natural breaks and added to the table of contents.

Below is an example of the Grid thematic layer. A thematic layer is produced and symbolized by an attribute you choose. The yellow grid cells contain the lowest total value of the selected attribute and the red grid cells contains the highest value.

The blue dots represent restaurant locations. For this example, each location has a total sales figure attached to it and each point has been joined to an underlying census tract layer. These grid cells are symbolized by the restaurant sales volumes now aggregated in the census tract layer.

Below is an example of the Grid attribute table. This attribute table is directly related to the thematic output above. The fields in the blue box are typical in the Grid attribute table and are automatically generated to describe the individual cell IDs. The A_Area_ID is automatically generated by concatenating the COLUMN_ID and ROW_ID fields. This produces a field suitable for labeling each cell similar to a bingo table. The SALES_VOL and NUMBER_EMP fields come from the restaurant point database. The SALES_VOL is used as the main symbolization value. The 2007 Total Population field represents a variable that is not symbolized on the map but the data is aggregated for each cell and included in the attribute table. This variable comes from the census tract layer.

Below is an example of the Grid layer added to the ArcMap table of contents. The grid values are added to the Table of Contents, as shown below, and automatically separated into a Natural Breaks classification. You can modify the classes and symbology in the Layer Properties. Restaurant sales value is used to symbolize the grid cells here.

Learn more about Hot Spots (Grids).