| Geography 4050 / 8056
| Dr. Michael Peterson
264 (through 260); 554-4805
Data to Maps with ArcMap
downloading a map and a data file.
- Go back to the GIS default page and right click on the Download Election Map
- Choose Save Target As and save the
file as a zip file named Omaha_94.
- Also, right click on the Download
Election Data link
- Save this file and name it 94electiondata (this
file is a dbf file).
the ZIP file:
- Go to the Start menu
in the bottom left-hand corner of the screen
- Go to Programs, then to EnZip.
Click on File and Open Archive.
- Navigate to where you saved Omaha_94.zip.
Double click on Omaha_94.zip
- Choose the extract
icon (fourth icon from the left that looks like a folder)
- Keep the name Omaha_94
and click on extract.
Now you have a file and
folder, both named Omaha_94
- Click on the Start menu
- Go to Programs, then to ArcGIS
and open ArcMap.
- Select create A new empty map and
- Click on the
Add Data button to add data.
- Navigate to where you saved Omaha_94
and double click on it.
- Double click on
- An error massage
might come up. Click OK. Now a map of Omaha should appear in the
- This is a good time to save your project.
Under File, go to Save As... and save this project as
- The next step is to join an external data table
with your shapefile. This can be done when the data in the tables has a
on-to-one relationship. This means that one attribute row in both tables has
to be the same.
- To first import the
data table click the Add Data button, navigate to where you saved the
94electiondata.dbf and click Add.
- This should automatically add a table symbol
with the name 94eclectiondata.dbf underneath your Omaha_94.shp layer.
- To now join this table to the Omaha_94
shapefile right-click on the Omaha_94.shp layer, point to
Joins and Relates, and click Join.
In the Join Data which opens click the first
dropdown arrow and click Join attributes from a table.
the second dropdown arrow and click the field name in the layer on which the
join will be based (CODE).
Click the third dropdown arrow to choose the table to join to the layer
- Click the
fourth dropdown arrow and click the field in the table on which to base the
- The CODE column in the shapefile table and
the WARD_PREC column in the 94electiondata both index the other attributes
- Click OK.
- The attributes of the 94electiondata.dbf are
now appended to the Omaha_94.shp layer's table.
- Double click on the Omaha_94.shp, this will bring up the Layer
Properties window. Choose the Symbology tab and click Quantities.
Choose graduated color, then select the Value
to one of the four candidates that you would like to map.
There will be a lot of choices, the four that you need are Kerry,
Stoney, Hoagland, and Christensen, choose one. Next
select a color scheme that you want. (To get a color scheme click
on the color ramps, choose a color and click apply)
- Also, create a map that compares a
democratic vs. a republican candidate. Map out one candidate and make
two classes with the break at 50%. Numbers over 50% indicate where the
candidate you mapped out won, votes under 50% count for the opposite
- The title of the legend must now be changed.
Double click on the Omaha_94.shp, move to the General tab, highlight the
Name and change it to something relevant to the map with the
appropriate candidate's name and click ok.
- SAVE your project again by selecting save
in the file menu.
organizing a Layout...
- Under the View window, select
Layout View. Create a Layout based on the descriptions of exercise
1 (Omaha Census).
- Once you are happy with the layout, select
File-Export Map to save the map to pdf.
Name your file accordingly.
- Submit the map to your web server
folder as ker.pdf, ston.pfd, hoag.pdf, or chris.pdf.
Updated by Kristie Raymond, 9/9/02, further updated by Eva Grund, May