1. 1. OpenStreetMap (+ other Geo/Ruby things) Sheffield Ruby User Group July 2015 Tim Waters tim@geothings.net @tim_waters
2. 2. Live OSM http://live.openstreetmap.fr/ https://osmlab.github.io/show-me-the-way/
3. 3. What is OpenStreetMap? A web project to create a free and open map of the entire world
4. 4. History * Founded in the United Kingdom in 2004 by Steve Coast * Ordnance Survey Data was Expensive to Use * July 2005 the First Mapping Party Takes Place
5. 5. Open Data
6. 6. http://www.ted.com/talks/view/lang/en//id/788
7. 7. Haiti http://vimeo.com/9182869 ito_haiti_berners_lee.mp4
8. 8. Dude, we just use Google.
9. 9. The reasons not to... Terms of Use Copyright Derived Works No Data OSM better in many areas
10. 10. Dude, you can't trust it
11. 11. Wikipedia Fix the data Objectiveness Quality Control
12. 12. Statistics Number of users 1,045,770 Number of GPS points 3,295,708,898 Number of nodes 1,788,120,111 Number of ways 171,187,609 Active users / month 17,478 Wikipedia: Number of pages: 29,551,074 Number of articles: 4,173,959 Active users / month 135,706
13. 13. How do people map?
14. 14. YOU CAN GET THE DATA
15. 15. YOU CAN GET THE DATA 1) direct dump planet (26G Compressed) whole, day, hour, minute 2) API i.e. OverPass 3) Extracts Shapefile format (buildings, natural, place, rail, roads, water, points, landuse)
16. 16. Overpass API
17. 17. TagInfo http://taginfo.openstreetmap.org/
18. 18. Slide taginfo for a tag
19. 19. Literally More data than appears
20. 20. More data than appears
21. 21. Literally more data than appears Cartography
22. 22. Stamen - Watercolor http://maps.stamen.com/watercolor/#15/53.80 25/-1.5469
23. 23. Stamen Toner
24. 24. Literally more data than appears Custom Maps
25. 25. OpenStreetMap Schema Folksonomy: collaboratively created created system of tagging things. (The community creates the OpenStreetMap tagging scheming over time)
26. 26. Nodes, Ways and Areas
27. 27. OSM Stack Website API Editor Map Rendering Exports
28. 28. OSM Website Ruby on Rails Github openstreetmap/openstreetmap-website All volunteers
29. 29. Suitable tasks Changeset reverter, history diffs History bounding box improvements Groups of users Area type
30. 30. Rosemary Ruby library 4 OSM https://github.com/sozialhelden/rosemary require 'rosemary' api = Rosemary::Api.new node = api.find_way(174111099) #"pub", "building"=>"yes", "food"=>"yes", "name"=>"The Red Deer", "real_ale"=>"yes"}>
31. 31. Rosemary client = Rosemary::BasicAuthClient.new ('osm_user_name', 'password') api = Rosemary::Api.new(client) changeset = api.create_changeset("Postbox on Timothy Leary Street") node = Rosemary::Node.new(:lat => 52.0, :lon => 13.4) node.add_tags({"amenity"=>"postbox"}) api.save(node, changeset) api.close_changeset(changeset)
32. 32. OSM Stack OpenHistoricalMap OpenGeoFiction
33. 33. OpenHistoricalMap
34. 34. Saeby Denmark 18C
35. 35. Saeby Denmark Now
36. 36. OpenGeoFiction
37. 37. Other ruby geo (GIS) Geos Gdal Rgeo Mapnik
38. 38. GEOS defbuffer(feature,radius,min_radius=0.0) wkb_writer=Geos::WkbWriter.new wkb_reader=Geos::WkbReader.new geom=wkb_reader.read_hexfeature.geometry buffer_geom=geom.buffer(radius) ifmin_radius!=0.0 hole_geom=geom.buffer(min_radius) buffer_geom=buffer_geom.difference(hole_geom) end feature.geometry=wkb_writer.write_hexbuffer_geom feature end https://github.com/dark-panda/ffi-geos Apt-Get install libgeos-ruby
39. 39. GDAL / OGR https://github.com/zhm/gdal-ruby Gdal::Ogr.create_geometry_from_wkt('POINT (30 10)') raster = Gdal::Gdal.open(filename) dx = raster.RasterXSize dy = raster.RasterYSize x0, x_res, x_skew, y0, y_skew, y_res = raster.get_geo_transform
40. 40. RGeo https://github.com/rgeo/rgeo factory=Rgeo::Cartesian.factory point1=factory.point(1,0) point2=factory.point(1,4) point3=factory.point(2,0) point4=factory.point(2,4) point2.distance(point3)#=>5.0 line_string1=factory.line_string([point1,point2,point3]) line_string1.num_points#=>3 line_string1.point_n(0)==point1#=>true line_string1.end_point==point3#=>true
41. 41. PostGIS / postgres https://github.com/rgeo/activerecord-postgis-adapter create_table:my_spatial_tabledo|t| t.column:shape1,:geometry t.geometry:shape2 t.line_string:path,srid:3785 t.st_point:lonlat,geographic:true t.st_point:lonlatheight,geographic:true,has_z:true end
42. 42. PostGIS / postgres record=MySpatialTable.find(1) p=record.lonlat#ReturnsanRGeo::Feature::Point putsp.x#displaysthexcoordinate putsp.geometry_type.type_name#displays"Point"
43. 43. PostGIS / postgres bbox_polygon=Polygon.from_coordinates([bbox_coords], 4326).as_ewkt Model.where(ST_Within(bbox_geom, ST_GeomFromText('#{bbox_polygon}'))")
44. 44. Ruby Mapnik :-( https://github.com/mapnik/Ruby-Mapnik Gem maintainer gone? Code = old & broken But Mapnik = how maps are rendered from postgis from OSM Everyone uses it C++ (rice)
45. 45. map=Mapnik::Map.newdo|m| m.background=Mapnik::Color.new('#777')#Agreybackground #UsetheGooglemercatorprojection m.srs=Mapnik::Tile::DEFAULT_OUTPUT_PROJECTION #Addalayertothemap m.layer'countries'do|l| l.styledo|s| #Addaruletothestyle(thisoneisadefaultrule) s.ruledo|default| default.fill=Mapnik::Color.new('#880000') end end l.srs="+proj=latlong+datum=WGS84"#setthesrsofthelayer l.datasource=Mapnik::Datasource.create:type=>'shape', :file=>"myshapefile.shp" end end map.zoom_to_box(map.layers.first.envelope) map.render_to_file('my_map.png')
46. 46. Thanks! @tim_waters Leeds Ruby Thing last Thursday every month