A density grid is a way to visualize and analyze point data by transforming the points into a regular grid. Each resulting grid cell is assigned a value that is determined by the density of nearby points, optionally weighting each point using a weighting value. Density grids are useful for showing hot spots of crime, mapping the concentration of healthcare providers, and analyzing the pattern of clients around a store weighted by the cost of their purchases. This Tech Tip shows how to work with the Density/Heat Layer tool in Maptitude:
The steps below show how to create a density map of the concentration of physicians, but you can use any point layer (such as customers or crime locations) as the basis for your map in step 5.
- Download the free healthcare data layers.
- Use the Create a United States Map option from the Home Window to create a map of any U.S. county (e.g., Los Angeles CA, Cook IL, Harris TX).
- Click on the Standard toolbar and add the Physician layer (ccPhysician.cdf) that you downloaded in step 1 to your map.
- Choose Tools>Analysis>Density/Heat Layer or click on the Standard toolbar.
- Choose Physician from the Layer drop-down list and choose Visible Features from the Set drop-down list. (Note: You are going to create a heat map showing the density of all physicians in the county. If you wanted, you could focus on a subset of the physicians by using a selection set such as just the physicians whose primary field is geriatrics or orthopedics.)
- Enter 2 in the Radius edit box (to assess the density of physicians within 2 miles of all locations in the grid) and make sure the Theme box is checked.
- Enter a name for the density grid layer, such as "Physician Density," in the Layer Name edit box.
Maptitude computes the density grid and adds it to the map. The density at any location will be given by the shading of your default color theme - usually light to dark green for low to high density. You may want to hide the Physician layer to better see the density grid.
For a tutorial on density grids, see: https://www.caliper.com/learning/media/creating-a-maptitude-hot-spot-density-grid-map/