The Thematic Mapping function allows you to choose a data set and display it on a map using a color scheme and a solid or pattern fill. For example, you can display counties in various colors based on the Median Household Income.
When you first enter the 1990 Census database in LandView® choose a geographic entity that you would like to see displayed by clicking on the appropriate tab. In order to look at data for counties in Maryland for example, one must perform a query. Therefore, click on the Counties tab and then click the Query button. Once the query screen appears, enter the state abbreviation in the field box labeled State and hit Enter. When the data for counties in Maryland appears, click in the field box next to the data item of interest. Those boxes marked with a percent sign, will be calculated based on the percentage. If you are not looking for a result based on the percentage then do not highlight the percentage field box. Once you have highlighted the appropriate field box you can then click on the Thematic Mapping button. If you do not first select a data item, you will receive a pop up message telling you to do so.
Once in Thematic Mapping, a set of four number ranges should appear. (In some situations this may not be the case.) The system determines the values of the selected data item by choosing number ranges that approximate an even distribution of records among the four or less categories. (Note that the system may take a little time processing if the number of records is large.)
If you wish to change the quartile values clicking on a number under To or From will highlight the number ranges and allow you to plug in your own ranges. Click Recalculate Record Count when you are done. This will allow the system to redistribute the records. If you would like to change the title then simply click on that area and a text box will be displayed so that a change can be made.
There are four color schemes to choose from to display the map as well as a choice of a solid or pattern fill. Once you have your display pattern and number ranges set, select Show on Map and a map will be displayed in MARPLOT®.
When you no longer want to view the map objects in a thematic fashion, go back into LandView and click the Cancel button in the thematic mapping window. This will bring you back into the Census database. If you go back into MARPLOT after canceling the map in LandView, MARPLOT will return to its normal way of displaying objects.
Source: U.S. Census Bureau
Last Revised: Thursday, 26-Jan-2012 17:47:52 EST