Editing Automatic label placement (section)

'''Automatic label placement''', sometimes called '''text placement''' or '''name placement''', comprises the computer methods of placing labels automatically on a map or chart. This is related to the [[Typography (cartography)|typographic design of such labels]].

The typical features depicted on a geographic [[map]] are line features (e.g. roads), area features (countries, parcels, forests, lakes, etc.), and point features (villages, cities, etc.). In addition to depicting the map's features in a geographically accurate manner, it is of critical importance to place the names that identify these features, in a way that the reader knows instantly which name describes which feature.

Automatic text placement is one of the most difficult, complex, and time-consuming problems in mapmaking and [[Geographic information system|GIS (Geographic Information System)]]. Other kinds of computer-generated graphics – like [[chart]]s, [[graph of a function|graph]]s etc. – require good placement of labels as well, not to mention engineering drawings, and professional programs which produce these drawings and charts, like [[spreadsheets]] (e.g. [[Microsoft Excel]]) or computational software programs (e.g. [[Mathematica]]).

Naively placed labels overlap excessively, resulting in a map that is difficult or even impossible to read. Therefore, a GIS must allow a few possible placements of each label, and often also an option of resizing, rotating, or even removing (suppressing) the label. Then, it selects a set of placements that results in the least overlap, and has other desirable properties. For all but the most trivial setups, the problem is [[NP-hard]].