The Color Theme (Multiple Fields) add-in provides you with a new
way to visualize and compare multiple fields of data. Also known as
plurality
maps, predominance maps, relationship maps, bivariate maps, or multivariate
maps, multiple field themes can reveal patterns
and let you see how items are connected. This is achieved using a method
known as multivariate choropleth mapping, in which multiple color
ramps merge to display all pattern combinations in a grid-like
legend.
To install:*
- Download the file color-theme-multiple-fields-addin.exe.
- Double click the executable to launch the installation.
- Confirm that you would like to allow the installer to make
changes to your PC and follow the instructions in the
installation wizard.
- Once installed, the add-in can be launched by opening a
Maptitude map and choosing Tools>GIS Developer's
Kit>Add-Ins>Color Theme (Multiple Fields).
*NOTE: The Color Theme (Multiple Fields) add-in works only with
Maptitude 2024.
To Add a Multiple Fields Color Theme to a Map
- Make an area layer the working layer by choosing it from the
drop-down list on the Standard toolbar or right-clicking in the
Display Manager and choosing Make Working Layer.
- Choose Tools>GIS Developer's Kit>Add-Ins> Color
Theme (Multiple Fields) to display the Color Theme
(Multiple Fields) dialog box.
- Choose whether to apply the theme to All Records or a
selection set using the Records drop-down list.
- Click Choose Fields to display the Choose
Fields dialog box.
- Highlight up to ten fields in the Available Fields scroll
list and click Add>> and then click OK.
- MapWizard fills in the other settings in the dialog box.
Modify any of the other settings as follows:
To do this... |
Do this... |
Change the legend
labels for a theme class |
Edit the text in
the Label column |
Change the color of the theme class
palette |
Choose a color from the drop-down
list in the Color column |
Choose the total field to convert to
percentages |
Choose a field from the Denominator
drop-down list (e.g., population, households) |
Change the number of ranges |
Choose from the # of Classes
drop-down list |
Modify the ranges for the classes |
Enter different values in the Low %
or High % columns |
- Click OK. Maptitude draws the map with the
color theme and displays a legend.
Try it Yourself
- Choose File>New Workspace, choose
to create a new map of the United States, then click OK,
and Finish.
- If the County layer is autoscaled off, make it visible and
make it the working layer.
- Choose Tools>GIS Developer's
Kit>Add-Ins>Color Theme (Multiple Fields).
- Click Choose Fields.
- Filter by typing in the "hisp" in the edit box.
- Highlight [Hispanic Origin],
[Not Hispanic White], and [Not Hispanic_Black].
- Click Add>> and click OK.
- In the Denominator drop-down list choose Population.
- Leave the number of classes at 4, and enter 25, 50, 75, and
100 in the High % column.
- Click OK.
Tips for Choosing the Denominator
The Color Theme (Multiple Fields) add-in determines the
percentages of each field that you use to determine which field is
contains the plurality for an area. When comparing fields of
populations or households the demoninator is straightforward. In
other cases, you may need to create a formula field that contains
the total value for the denominator. For example, you may have
fields for counties that contain the Democrat, Republican, and Other
votes from an election. To create a plurality theme map showing the
party receiving the most votes in each county, you will first need
to create a "Total Votes" formula field that is the sum of those
three fields to use as the denominator.
Tips for Setting the Ranges
You may want to adjust the values used in the ranges depending on
the data that you are mapping. Suppose that you have fields with the
number of McDonald's, Burger King, Wendy's, and Sonic stores in each
state and a formula field that is the sum of the four stores:
- If you want to know which is the predominent store in each
state, then at least one store must have greater than 25% of the
market so the first range should not be less than 25%. In this
case, you may want to use ranges of 0-30%, 30-40%, 40-50%, and
50-100%.
- On the other hand, you may want to know, aside from
McDonald's, what is the predominant store in each state. In this
case, you could have a chain with a plurality that is less than
25%, so you may want to use ranges of 0-10%, 10-25%, 25-50%, and
50-100%.
If there is not much variation within the ranges for your theme,
you may want to run the add-in several times adjusting the values in
the ranges until you get a plurality map that is more meaningful.