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4.3. Maps

The map files used by WinDisp3.5 are in the ATLAS*GIS export format. The file type supported are point, line and polygon. These files, unlike the IDA images format used by WinDisp3, are in ASCII format and can be viewed and edit using a text editor.

The ASCII file consists of sequential lines of text with no spaces (except in the feature name). Each line ends with a carriage return. The first line for a feature contains one or two feature labels of up to 16 characters surrounded by double quotes, followed by a comma and then the number of points that describe the feature:

Each line following the feature name line should contain the longitude, comma, latitude for an endpoint in decimal degrees. After the last endpoint, a new feature may be started. Limitations are 1,100 endpoints per feature, 3,000 endpoints per file and 200 features per file. The following is an example of a map file with one point, one line and one polygon.

The following are the basic models of the formats required for the point, line and polygon files:

The following city map for Burkina Faso is an example of a point file:

The following river map for Burkina Faso is an example of a line file:

The following island (country) map for Cape Verde is an example of a polygon boundary file:

The second label for a feature name is optional: it may or may not be there. While the first label normally denotes the name of the feature, the second one can be used to point to a larger geographic entity to which the region (polygon) or point belongs. However, the user is free to use both labels to his own liking.


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This manual was prepared by the Global Information and Early Warning System of the United Nations Food and Agriculture Organization
© FAO/GIEWS - 1999
E-mail: Giews1@fao.org