Introducing Geographic Information Systems with ArcGIS: A Workbook Approach to Learning GIS, 3rd Edition

How the Computer Aids Analyzing Spatial Data

Computers can aid in spatial data analysis and synthesis in a variety of ways. First off is speed. It helps that computers can add and compare numbers billions of times faster than you can. (Computers, while stupid, are fast and accurate. Humans are smart, but slow and sloppy.) Further, a computer is capable of doing repetitive tasks (read: boring) for hours or years on end. You probably would not want to know a person with this capability. A third virtue of computers in GIS is the ability to store very large datasets.

A vital factor in using a computer to analyze spatial data is the paradigm or schema (data model, data structure) that is used to store the data in the memory of the machine. While the issues about the format in which to store data are not unique to GIS, lots of other fields have much less of a problem. Usually when one stores data in a computer, the questions that arise are ones like the following:

• Should I use integers or numbers with decimal points?
• Is the number likely to be very big or very small?
• Would it cause problems if I used a text string to store a numeric value?

Such sets of numbers usually exist in simple lists, databases, or perhaps in matrices.