Geographical Information System Example

Input Data

• are gathered by a catalog-order company from sales of its products over a 3-year period (650,000 customers).
• contain attributes: customer number, state where customer lives, number of orders made by customer, total number of products ordered by customer, total amount of money spent by customer.

The input file looks like:
1036852,CA,15,40,976
1036872,HI,4,20,840
1037049,CA,5,17,403
1037459,NV,12,38,812.5
1037759,IL,6,25,653
1038606,MN,10,39,945
...

Problem

Visualization

The visualization is created as follows:

1. Define window titled "Geographical Data" showing a geographical area of interest. Location of customers is shown on top of the US map. Customer's state code is mapped to the latitude and longitude of some major city in the state, plus some randomness to create a cloud for easier separation between customers. The total amount of money spent by the customers is indicated by size and color of rectangles.
2. Duplicate window and title it "Geographical Data 2". This window shows the global picture, with a colored rectangle indicating the area displayed in the first window. The rectangle is a visual cursor which can be moved and resized with the mouse.
3. Define window titled "Sales Data Display" showing the total number of orders, total number of products purchased, and the total amount of money spent by customer.
4. Link the X axes of the views in "Sales Data Display".
5. Create record link from "Geographical Data" to "Sales Data Display".
6. Select an area of interest in "Geographical Data" and the system displays the corresponding data records in "Sales Data Display".

Observations

1. This example illustrates the ability of DEVise to handle large amounts of data. About 6 MB of memory buffer is used to visualize 20 MB of data (650,000 customers).