View source for OHM

'''Open History Mapper''' is a project, in its early stages, whose main goal is to be an open alternative to [http://wals.info WALS].

== The need / uses ==
The primary use of OHM is to map linguistic features in modern languages (like WALS), but it can be used for so much more.  Various ways it could be used include the following:
* Mapping linguistic features, like WALS.  This doesn't have to be limited to typological features like WALS, but can be used for etymology (e.g., to visualise the geographic extent to which reflexes of a various word or form are used).
* Mapping historical sociology stuff.  For example, one could look at the prevalence of various causes of death per region in 1800s Russia, given that the data were available.

== Features ==
The software should allow users to easily
* define arbitrary areas or points,
* specify a name for the areas or points from predefined [perhaps user-generated] data (e.g., a list of languages, etc.),
* map features to areas or points (even those defined by others),
* subgroup areas and points,
* display maps of the areas and points corresponding to various values of a feature, distinguished e.g. by colour,
** ideally include customisable and complex symbology—e.g., provide ability to display multiple features at a time, using different distinguishing properties (colour, texture?, etc.),
** include a customisable (in terms of look, content, and placement) legend, which may include the option to switch quickly between displaying different features,
** include d3-like mouse-hover information on areas and points,
* [down the road] upload a scanned map and geo-reference it,
* export maps for use in publications.

== Software ==

=== Mapping core ===
The mapping core that will be used hasn't been decided on yet.  Some possibilities include the following:
* [http://openlayers.org/ OpenLayers] — very powerful, but a little tricky to use?
* [http://leafletjs.com/features.html Leaflet] — fairly powerful, easy to use
* [http://polymaps.org/ Polymaps] — seems to do a lot of cool stuff, easy to use, powerful enough?

Given the desired [[#Features|features]], the core mapping software should support the following:
* the ability to [http://openlayers.org/dev/examples/draw-feature.html draw points and polygons], as well as [http://openlayers.org/dev/examples/highlight-feature.html select], [http://openlayers.org/dev/examples/modify-feature.html edit] (e.g., [http://openlayers.org/dev/examples/donut.html trim stuff away], [http://openlayers.org/dev/examples/modify-feature-bysegment.html adjust points], delete points, insert points, etc.), and [http://openlayers.org/dev/examples/marker-shadow.html move] them,
* ideally, the ability to [http://openlayers.org/dev/examples/polar-projections.html display the same data in different projections] (maybe a simple political background map would do this okay, but terrain wouldn't?),
* plot a bunch of stuff and have a nice legend for it (see above),
* an [http://openlayers.org/dev/examples/overviewmap.html overview map] would be nice,

=== Base maps ===
There will need to be base maps in various projections.  Some requirements follow:
* Projections that preserve size are ideal due to the nature of what these maps will be used for.
* Background layers should include physical maps of the earth as well as modern political boundaries and names.  Use of one or the other or both should be easily user-switchable.

==== Physical map options ====
* Perhaps the technology behind [http://maps.stamen.com/terrain/ Stamen's terrain maps], but with a wider set of data (like [http://wiki.openstreetmap.org/wiki/SRTM SRTM])?
* [http://www.mapbox.com/blog/2012-08-28-mapbox-streets-landcover/ MapBox terrain cover], [http://www.mapbox.com/tour/#section-terrain MapBox terrain] – very nice, but have to pay for API
* [http://mike.teczno.com/notes/osm-us-terrain-layer/foreground.html OSM Terrain layer] / [http://wiki.openstreetmap.org/wiki/TopOSM TopOSM] – only covers US :(
* [http://devblog.mapquest.com/2012/10/16/terrain-added-to-mapquest-osm-tiles-other-updates/ MapQuest OSM terrain tiles] ([http://developer.mapquest.com/web/documentation/open-sdk/javascript/v7.0 Javascript developers guide]) – requires API key, can't be separated from OSM data
* [http://www.arcgis.com/home/webmap/viewer.html?webmap=68a4f59815c745eeb2fa161f6ea0c112 Natural Earth physical map] – resolution sucks
* [http://www.arcgis.com/home/webmap/viewer.html?webmap=3c93bbf238424a3e85aae19823fc92ea&level=8 Natural Earth shaded relief map] – too basic
* [http://ifgi.uni-muenster.de/worldwind-tutorial/ World Wind] ???
* See [http://glottolog.org/resource/languoid/id/noga1249.bigmap.html#12/43.5916/46.6619 for good stuff] !

== Features that could be fun to map ==

=== lateral inventory ===
Seems relevant especially across Eurasia.  Values are: light only, dark only, retroflex only, one category with allophonic variation, two-way distinction, three-way distinction.  Perhaps very light (e.g., for French as compared to Spanish) and very dark would be good categories to add too.