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Mapping tabular data and classifying it specific groups

October 19 2007 | 0 comments
Categories: Cartographic Design, Map Data

I am trying to map a number of people who have a specific number either 0, 2, or 4.

My attempt is to present data such that each dot is shaded to show the degree from 0 through 4, and each dot is sized to show how many have that range.

I have multiple field tabular data that lists county, lat/long, radon concentration detected in the home at the given lat/long, and population of that county.

I would like to show the radon concentration with different colors, and have graduated symbols size to reflect the number of homes with that given concentration.

The concentration data are from 0.0 to 225.0 with various decimals in between. I only care if the concentration is 0, <=2, <=4, or >4.

Is there an easy way to do this?

Mapping Center Answer:

I think the easiest way to get this done it to load the tables into ArcMap as “event layers” and symbolize them using the standard layer symbol properties. You’re going to need to do a bit of data summarization if you want to associate the total of homes within a county with the concentration classes you want. Use the Summary Statistics tool to do this.

In the Layer Properties Symbology Tab, select the Quantities à Graduated Symbols symbol type and define the classes. You can then manually manipulate the symbol size and color to whatever works best for you. I’ve included a screen shot of some dummy data that is my interpretation of what I think you’re looking for.

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