FOSS4G 2011

Here are some raw notes from my FOSS4G workshops & sessions so far. Enjoy!

Mapnik & TileMill workshop

• Presented by Development Seed
• You should learn Python & node.js
• TileMill used in today's example
• TileStream used to serve tiles
• TileStream hosted is $50/mo for only five 1GB .mbtiles files
• On IRC, visit #mapnik
• TileMill Windows client planned in 2 months
• Python sample
  • - import mapnik2
  • - m = mapnik2.Map(256, 256)
  • -- Python error
  • - type a module name to list from where it was imported
  • we attempted to install mapnik2 from source but it didn't work, on to TileMill
• TileMill is a website, control room
  • - add data/layer
  • - can view data attributes
  • - geojson/spatiallite via OGR
  • - how does OGR do lat/lng vs x/y?
  • - drag drop layer order
  • - save to update map w/ new CSS
  • - carto is LESS CSS-like language, .mss files, link for reference
  • - has variables
• new project
  • - change Map background-color, save
  • - new layer
  • - postgis, connection string
  • - postgres command line
  • -- psql -l (list databases)
  • -- psql database-name
  • -- \d to list tables
  • - error mapbox is undefined
  • -- auth error, check username and password
  • - if no rule, nothing renders for layer
  • - #data { marker-width: 2; }
  • - [highway='traffic_signals'][zoom>=10]
  • - assumes spherical Mercator
  • - wrench=>view mapnik XML link
  • - subquery as data source: (select name from roads where ST_Length(way) > 8000) as longroads
  • - that ending as is required
  • - line::case is border, line::fill is fill? these rules were confusing
  • - carto has a command line, export as mml
• MBTile
  • - embeds every feature id in tile as JSON in tile itself
  • - replace .png with .grid.json to see all feature data
  • - follow TMS standard
• Modest maps, web mer JavaScript api
• Export
  • - preview is only for MB tiles
  • - download MB tile
  • - cp to ~/proj/tilemill/files/export/
  • - browse TileMill (:8888)/#!/ for list
  • - you do have access to the .grid.json file
• TileStash renders mapnik to amazon
• Fast maps
• - ab tool to profile requests / sec
• - Proj 4.8 doesn't lock as much
• - OGR has trailing spaces in proj4 string, can cause mapnik to reproject on fly to same projection, be careful

node.js & Polymaps workshop

• Github proj, chelm/FOSS4G-Node.js...
  • - network issues preventing start by 1 hour
• npm - node package manager
  • - search packages on website
  • - geonode - GEOS wrapper on node.js
  • - express & socket io to be talked about today
• node
  • - evented framework = callbacks
  • - callbacks don't block the thread
  • - commonjs modules
  • -- hello.js: exports.myvar = function () ...
  • -- require ('./hello')
  • - only one thread, don't block it yourself
• express
  • - req.query is an object
  • - template engine called jade
  • -- response.render( 'template.jade', args)
  • -- look in views dir by default
• EventEmitter
  • - emit(eventname, args)
• Ticker.prototype = new EventEmitter adds emit & addListener to Ticker function object
  • - prototypical inheritance
• Twitter
  • - npm install twitter-node
• Polymaps
  • - all svg
  • - styled with CSS
  • - can embed canvas in svg element for dynamic color changes
  • - tiles & geojson
  • - vector tiles?!
  • - but only TtileStash creates vector tiles so far
  • - clusters on load, not on the fly
  • - 38k minified
  • - lots of .add(po.functionality()) chained
  • - .on("load", function ( data ) { data.features[0].element } )
  • - CloudMade has hosted tiles once you register
  • - colorbrewer - gis color ramps in JavaScript
  • - protovis - data analysis, Scale.quantile, etc.
  • - geocommons, datasets available via .json extension
  • - using jQuery for events
  • - map.coordinateLocation function
  • - socket io using web sockets to bind client handlers to server events

State of PostGIS

• paul ramsey
• database is types, indexes & functions
• spatial database just adds spatial to to those three
• mysql is STILL not a spatial database
• arcsde was never a spatial database, it's middleware. also, it's going away
• history of postgis versions
• native support by esri in arcgis server
• "not as cool as new kids" CouchDB, etc.
• we're "yesql"!
• postgis has prepared geometry
  • point in polygon is O(n), but indexing edges brings it to O(log(n))
• supports curves
• 2.0 out in six month-ish

Oceans using OGC services

• scientists & tech guys working together
• data comes from scientists in all formats
• filter by time & depth, the ocean is "4D"
• Flex thin client, many filters
• ncwms? wms that serves up nc? data
• scientists willing to take a cut in performance in order to see the data
• LarvaMap, find where larva are floating, they can't swim after they hatch
• NetCDF, open source server over HTTP for large data sets
• OGC-Search, find WMS services
  • Metadata isn't updated, a problem for search
  • version 2, bbox search
• Environmental Data Connector pulls open source data into ArcGIS
• github/asascience

Geomagas

• Native
  • - pro: all device sensors
  • - con: app stores
• mobile web
  • - caniuse html5, html5 isn't everywhere yet
  • - JavaScript is slow
• Current geomajas
  • - Java is both dev & test environment
• Gwt
  • - works w/ mobile
  • - only sends code you use
  • - one html file is everything
• Future
  • - all Java, split common api out for android & blackberry
  • - combine layer tiles on server
• Demo
  • - android native browser missing svg, using Firefox for mobile demo

Opticks

• comet created for USAF
• open sourced in 2007, bringing internal code over in parts
• why open source?
  • hard to get other gov agencies to use it otherwise: "not invented here" syndrome
  • Ball Aerospace is a service company, will never sell software
• problems?
  • contracted CollabNet to resolve open source confusion: doesn't mean just anyone can make code changes
• "geospatial infrastructure" first part open sourced
• lgpl, sourceforge
• multiple gov projects using opticks as foundation
• applied for OSGeo incubation
• no governace board but governace board required for OSGeo incubation
• all core contributors are or were Ball employees
• still slow from outside contributions; mostly bug reports and docs

Social Networks on OpenLayers

• started with valencia tourism geoportal
• OpenLayers 2.11 has a special jsonp protocol handler, fly..something?
• twitter & gowalla from POIProxy framework, pretty nice OpenLayers plugin
  • access to different POI services

Google Fusion Tables for flood mapping

• Had to be done in 90 days
• Fema nfhl can map flood planes but little control
  •  also not friendly
• Mashup w/ Google, points & poly
• No code change but suddenly 45 deg oblique imagery one morning
• Popup has links & data from fusion table
• Built Google table by hand
• Schema create statement generated via postgres select
• Postgres select to generate Google select
• Secret: load data with insert but send 500 inserts per request w/ semicolons between
• FT drops points over 500 per line
  • - they chopped the geometry by tiling scheme
  • - no geometry had more than 500 points
  • - better now on Google's side
• Cartography done via table, fill
• Very accurate
• Not enough carto options, they want cross hatching
  • - request sent, waiting for google
• Summary: worked very well
• Automated create / insert PHP scripts available vcfloodinfo.net
• Using free Google maps
• FT, only five layers allowed
• Can filter data on the map
• Very active group
• Can't use internal only due to Google license
• Shows ads

GXP

• For quickly editing sites
• GeoExplorer uses this library
• {ptype: gxp_legend, outputTarget: id}
• gxp_featuremanager, layer: { local, name: 'USA:streets' }
• From OpenGeo
• Like esri build an app, full website
• Feature editing with snapping to other layers
  • - gxp_featureeditor, snappingAgent:
  • - snapping agent references another layer
• github/opengeo/gxp
• Can use Google: map, street view, search
• Using openlayers behind the scenes?
• bartvde@opengeo
• No undo yet
• GeoServer-based authentication
• Can make plugins
• Other note: GeoGit new project adds versioning to geoserver from OpenGeo?

Using PostGIS with QGIS

• first use case for QGIS was only a postgis viewer
• now it's a gis platform
• version 2 coming, raster support & routing
• filter source table while loading as layer
• updatable view: a PostGIS view that can be edited in QGIS
• uses postgresql for authentication
• wfs-t support
  • http level rights (web auth)
• offline editing
• python plugins: pgVersion, subversion for postgresql
• fast SQL layer, dynamic queries (like ArcMap's Query Layer?)
• raster support
• DB Manager is the future?

OSM Plenary

• England combined vehicle time tracking to a map
• State of the Map, an OSM convention
• OSM Foundation
  • legal entity
  • maintains servers
• Sweet visual at itoworld.com
• OSM is about zoo mapping! ( also other things :)
• Wheel chair routing
• Address Hunter
  • address scavenger hunt game, multiplayer, find & take photo

FCC Plenary

• Communications is 7% of national GDP
• Time to market is #1 most important issue
• Obama issued Open Data Initiative
• Congress required data to be searchable
• FCC built REST services for block level data
• Pew Internet Research
• Intern threw together a mobile geolocation internet provider search on github quickly

MapServer status

• map server is old (project in mid-90s)
• 6.0 release with 6.0.1 security fix (upgrade!)
  • rendering plugin API
    • original was GD (8-bit gif)
    • 4 graphic backends shipping in 6 including OpenGL
  • expression parser rewrite
  • auto clustering, e.g., [6] graphic is six features, zoom in to see
  • built-in OpenLayers previewer
  • lots of WCS improvements, 2.0 support
  • multiple label styles per layer/shape, e.g., highway names and shields
• 25 source commiters, 13 PSC members (project steering committee)
• OSGeo project
• next
  • wfs-t support to postgis
  • built-in caching (MapCache) based on mod-geocache
  • svg symbol definitions (there's an RFC, but which one?)
  • auto-projection (also has an rfc, but which one?)
  • by "RFC" he means OSGeo-specific RFC proecess?

State of GeoTools

• actively committed project
• keeping up with bug reports
• dropped the 2. from version number 2.8 => GeoTools 8
• lots of doc updates
  • live code examples
  • 100,000 words
• referencing subsystem updated
  • more projections
• new vector data support: csv, directory of shapefiles
• new raster support: GeoTIFF, JP2, GRASS
• improved database driver
  • prepared statements
• new DirectLayer to write your own paint function
• StyleBuilder to help create SLD
• plugin will render custom SDL xml using your own Java code
• new transformation process for rendering or geometry processing
• process engine about to graduate to core functionality
• can now hook into Terradata data store
• temporal support
• query improvements
  • supporting joins in WFS queries

MapServer coverage support

• no one here is regularly using the coverage service
• wcs 2.0 standard is only a few months old
• three requests: GetCaps, DescribeCoverage, GetCoverage
• prereq: proj4, gdal, libxml2
• same format as layer in mapfile
• mapserver reads many coverage metadata attributes but none are required

Tile generation with Mapnik & Node.js

• open source version of fusion table
• CartoDB = tiler + Carto CSS + spatial SQL api + OAuth + UI
• view/edit data in UI via grid
• view/edit data on map via mouse & hover & drag
• live SQL query filter on map interface
• PostGIS on the back end for demo
• add columns on the table UI
• helps move some mapping back to server, mix with vector on the client
• Oops, "we wrote a map server"
• Amazon's main site is made from 300+ calls to 100+ HTTP APIs
• Tired of large map servers
• cute evented system example of boiling water for tea and going to the door to get a package
• no problems with the Mapnik stack
• github/Vizzuality

Mapnik2GeoTools

• mapnik definition
• mapquest's map design has 20 pages of styles, class breaks, etc.
• wrote a parser to export OGC filter XML
• put shapefiles & tiffs in data directory for geoserver
• process
  • run tool
  • open Mapnik file
  • click Convert!
  • look at output SLD file
• vendor mapnik option support varies
• misc
  • css has a different rendering model in geoserver, harder to convert from Mapnik
  • see also: mapnik distiller
• github/dwins/mapnik2geotools

• foss4g

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