Summary
There are three ways to create thematic maps, depending on data types and desired display options. Instructions provided describe each of the proceedures that can be used for ArcWeb Services 2.0.
Procedure
![[O-Image] Thematic Map flow chart](https://webapps-cdn.esri.com/CDN/support-site/technical-articles-images/000006212/00N39000003LL2C-0EM39000000wcll.png)
- Thematic Option 1:
These maps thematically display an ESRI-provided variable, such as population. Map Image Web Service determines how to display the data based on your class breaks and colors. To create these types of maps, use the method 'getThematicMap' with the input parameter 'thematicField'.
--Use the parameter 'thematicField' to set which variable colors the map.
To determine a list of available thematic field names, use the method 'getThematicFields'.
--To define class breaks and colors, use the other optional parameters. - Thematic Option 2:
These maps thematically display the data. Map Image Web Service determines how the data is displayed, using your class breaks and colors. To create these types of maps, use the method 'getThematicMap' with the input parameter 'thematicData'.
--Use the parameter 'geographyLevel' to set which geographic level is shaded (e.g. county). To determine a list of available geographies, use the method 'getThematicGeographiesForExtent'.
--To define the relation between geographic regions and data, use the parameter 'thematicData'.
For example, to pair a ZIP Code with a numeric value:
thematicData parameter:
key = 92373
value = 5
--To define class breaks and colors, use the other optional parameters. - Thematic Option 3:
These maps, like option 2, also thematically display the data but each region is colored individually based on your own coloring scheme. To create these types of maps, use the method 'getThematicMap' with the input parameter 'thematicData'.
--Use the parameter 'geographyLevel' to set which geographic level is shaded, such as 'county'. To determine a list of available geographies, use the method 'getThematicGeographiesForExtent'.
--Use the parameter 'thematic data' to define the relationship between each geographic region and a value for that region. Define the relationship between each value and a color with the CodeColorValues object.
For example, to pair ZIP Codes with descriptive types, and set a particular RGB color to each of these types:
thematicData parameter:
key = 92373
value = esri
key = 92374
value = not esri
key = 92371
value = not esri
colorCodeValues parameter (part of ThematicOptions object):
key = esri
value = 255,0,0
key = not esri
value = 0,255,0
--To define class breaks and colors, use the other optional parameters.