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6. Testing GISMO

It must be admitted that GISMO is a product of essentially very simple functionality. It has three main tasks to provide to the user:

  1. To provide an overview map, drawn from a set of UTM coordinate points,
  2. To allow the user to select subregions to zoom in on, and
  3. To allow the user to modify the color scale of the regions zoomed in on.
GISMO by definition will only take for its arguments files of data points in the UTM coordinate system. There are no complex boundary cases as such.

In order to insure that GISMO was producing accurate maps of Vancouver (our sample set of data), we did the following:

  1. Had our client, Dr. Snoeyink, personally view our maps and verify their accuracy.
  2. Checked our 2D maps against his 3D maps provided on one of his webpages (
GISMO unfortunately lacked a good "oracle" which we could use to verify the maps we produced. Dr. Snoeyink's 3D map-maker was a useful tool and the only thing that came close to serving as an oracle for GISMO.

Aside from drawing the maps themselves, we tested our methods of data extraction -- that is to say, that we verified that GISMO had correctly captured and stored all data points originally stored in the input files. In the final analysis, GISMO was difficult to implement but easy to test, because the product by its very specifications has a limited range of functionality. In the end, our most important testing was done in cooperation with our client when we verified with him that GISMO was doing what it was supposed to!