Installing the Cartogram tool for ArcGIS

Hi

Some of you may be ready to make cartograms from your worldmap_all layer.

BUT before you can start with this step you must have done the following 

1. Reorganised your spreadsheets so that all your data in available in one spreadsheet
2. Removed any repeated columns from your spreadsheet
3. Changed the column heading to 8 characters without spaces, brackets etc (remember to make a note of what your new headings mean!)
4. Join your spreadsheet to your worldmapper_all layer
5. Added a column or columns classifying the countries of the world into categories  (These will depend on  the question which you asked)

If you have completed all this you can start making the cartograms.

REMEMBER TO SAVE ALL THE YOUR WORK IN A SINGLE FOLDER AND EMAIL IT TO YOUR SELF!

Adding and using the ArcGIS Cartogram tool

We are going to try to do this today but the permissions on the lab computer may prevent us from getting this far. In which case we have have the script installed on the machine by next week and I will give you another task in the class.

In order to make the cartograms we have to add a special script to ArcGIS.  This script come with full instructions and its own data follow the steps below!

1. Download the cartogram tool script readme file (below) and read it carefully before doing anything else!  I know I don't I just click and get frustrated!!!!
2. Install the script to a folder which you create on the desktop e.g. desktop/ArcScripts.
3. Don't get confused you are here to learn!
4. The script installs its own demonstration .mxd file with its own layers and the tool already added to the toolbox. This is available in the cartogram .mxd file which is in the directory where you installed the script e.g. desktop/ArcScripts. You can use this demo to practice making a cartogram by following the steps in the readme file.
5. Once you have practiced making a cartogram using the demo data in the cartogram.mxd you can try with the worldmap_all layer using the data you joined to it from your spreadsheet in your .mxd file. 
6. If you read the instructions carefully - you will note the following when making a cartogrm using your data!

• You must add the tool to the toolbox - follow the steps in the readme file.
• Make sure there are no negative values in the value field you are using - this will be one of the columns you added with the join. You can do this by adding the definition query - all explained in the readme.
• DON'T PANIC!
• Check the box "Copy the Original Polygon Features table to the Output Cartogram Features table" or your cartogram will loose much of its attribute data such as country name which is no good.

Downloads

Cartogram tool readme file

Cartogram tool script

Remember not to panic and have fun!

Martin