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Map referencing tutorial 2 : Referencing

To reference a map you need to know the latitude and longitude for two points on it. Ideally these need to be somewhere near the south-west and north-east corners. Let's take the easiest case first, where these points are exactly at the two corners:-

By default the minimum and maximum extents of the map will coincide with these two points so the whole of this map (map2) will be zoomable.

Usually things aren't quite this simple.

More often, the two known reference points do not coincide with the bottom left and top-right corner of the map as in the next example.

Last Updated 23 July 1999

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