Chapter 14 - Making a Map
After making a table (Chapter 12) with the selected geography (Chapter 9) and the desired variables and values (Chapter 8), you can create a mapped visualization of the data. NOTE: Only one value for each geographic entity in the table can be mapped; i.e., the table cannot have variables nested vertically. If this is the case the map icon will not activate in the menu bar when values are highlighted.
The map icon will become active in the menu bar, depicted as a yellow shaded image of the U.S. once the values for mapping are highlighted in a table that is properly formatted:
Creating A Map
To create a map, highlight the variables you wish to map. In this example we are using the ACS 5-Year Summary File data, specifically U.S. citizenship by State:
After highlighting the values to be mapped, click on the Map Icon button and a map will automatically be generated:
The title of the map is the same as the column label that was mapped. You can specify the title of the map by customizing the label of the column/variable you are mapping by clicking in the cell above the first value and manually typing in the custom label:
Customizing A Map
Changing Map Window Size: To change the size of the map window, click on View ⇒ Map Size. Type in the desired width and height of the map window, then click ok. This feature is useful when saving the map image as a .jpg file or printing the screen for use in another document such as PowerPoint or Microsoft Word.
Changing Legend Classes: To change the Legend Classes (or Ranges) from the default value of 7, click on View ⇒ Legends ⇒ Legend Classes. Type in the desired number of legend classes, or ranges, and click ok. The map image will automatically redraw based on the new number of legend classes.
Changing Color Schemes: To change the color scheme of the map, click on View ⇒ Legend Types. You will see the other options to choose from:
Once you have selected the desired color scheme, click ok. The map image will automatically redraw based on the new legend type or color scheme.
Changing Minimum and Maximum Values for the Ranges: To change the minimum and maximum values for what is displayed on the map, click on View ⇒ Value Range. Type in the desired Start Value and End Value, then click ok. The map will automatically redraw based on the new minimum and maximum (start and end) values.
Customizing Interval Breaks in the Legend: To customize the interval break-outs for each range, click on View ⇒ Intervals. A window will pop up that allows you to type in specified ranges:
NOTE: The "FROM:" value in row/interval 2 must be equal to the "TO:" value in the row above it, i.e. "FROM:" value in Interval 2 must be the same number as the "TO:" value in Interval 1, and the "FROM:" value in Interval 3 must be the same number as the "TO:" value in Interval 2, and so on. Once the map is created, the legend on the map will automatically reflect the "FROM:" values as one increment higher for each range; i.e., it automatically calculates the "FROM :" value as a "plus 1" to begin the next highest range.
Changing Map Display and Legend to Quantile Intervals: To change the map display and legend from the default Equal Interval to Quantile, click on View ⇒ Map Type. Select Quantile. The map will automatically redraw to reflect the new quantile thematic ranges.
Adding Layer Boundaries: Depending on the level of geography being mapped; i.e., states, counties, census tracts, etc. that are available for selected datasets in DataFerrett, there is an option to turn on or off specific boundary layers:
Along with basic geographic boundary layers like states, counties, census tracts, etc. that can be turned on or off, there is also the opportunity to turn on a point layer ("Blue Dot") where appropriate. The "Blue Dot" layer displays address points assuming that a dataset containing appropriate latitude and longitude information has been tabulated and is being added to an existing thematic map.