Smallest-circle problem The smallest-circle problem in the plane is an example of a facility location problem (the 1-center problem) in which the location of a new facility must be chosen to provide service to a number of customers, minimizing the farthest distance that any customer must travel to reach the new facility. Both the smallest circle problem in the plane, and the smallest bounding sphere problem in any higher-dimensional space of bounded dimension, may be solved in linear time. Characterization Most of the geometric approaches for the problem look for points that lie on the boundary of the minimum circle and are based on the following simple facts: The minimum covering circle is unique.The minimum covering circle of a set S can be determined by at most three points in S which lie on the boundary of the circle. If it is determined by only two points, then the line segment joining those two points must be a diameter of the minimum circle. Linear-time solutions
OpenStreetMap Where is this? Reverse Directions Welcome to OpenStreetMap! Space-Time Research With self-service options offering enormous benefits in terms of speed, availability and cost, SuperWEB2 gives beautifully visualised ad-hoc tabulation on the internet. Featuring integrated charts, maps and metadata, users can help themselves to insights using their preferred browser, readily performing queries and selecting from a range of open standard outputs. With demand for timely information growing, SuperWEB2 offers self-service, web-based access to data for external, skilled users such as analysts, researchers and subject matter experts. Allowing government departments and other organisations to share information transparently, SuperWEB2 uses web-based ad-hoc tabulation to enable analysis across millions of table cells without compromising confidentiality. Previously, organisations offering any degree of transparency were limited to responding manually to information requests – a time consuming and often labour-intensive process.
Open source mapping software in the cloud To make it easy for you to get started with open source mapping software on own server, we provide server images including everything you need: PostGIS, MapServer, TileCache, GDAL, WFS, WMS, Elasticsearch, Leaflet and OpenLayers. Just launch an instance and start uploading your spatial data in only 5 minutes. After launch no configuration is needed, just start using your server and share maps with the world. Configuration of the servers:
Electoral college reform (fifty states with equal population) / fake is the new real The electoral college is a time-honored, logical system for picking the chief executive of the United States. However, the American body politic has also grown accustomed to paying close attention to the popular vote. This is only rarely a problem, since the electoral college and the popular vote have only disagreed three times in 200 years. However, it's obvious that reforms are needed. The fundamental problem of the electoral college is that the states of the United States are too disparate in size and influence. The largest state is 66 times as populous as the smallest and has 18 times as many electoral votes.
Documentation API Reference This reference reflects Leaflet 0.7. Docs for 0.6 are available in the source form (see instructions for running docs). Why all men should be able to read a map So here’s a quick refresher course: What is a map? Maps are simply an accurate 2-D rendering of the ground as seen from above, scaled down from life-size with symbols to show the landscape accurately including particular features such as roads, footpaths and landmarks. Learning compass points To understand maps you need to understand direction via the points of a compass: North, East, South and West. GeoSilk GeoSilk is a set of icons designed for open source web-based geospatial software. The set is an extension of Mark James's Silk icons—probably the most widely used set of icons on the web—that incorporates metaphors for spatial constructs defined by Jody Garnett's uDig icons. Take a gander at the full set or download it from the SVN repository. GeoSilk is available under a Creative Commons Attribution 3.0 License, meaning anyone may use it for any purpose and make any changes they like. Read GeoSilk: Icons for a shared geoweb on the OpenGeo Blog to learn more about this icon set.
Expanding Leaflet's format support with Omnivore Omnivore helps Mapbox.js & Leaflet eat more types of data. We love and support GeoJSON, but sometimes specific data is in other formats, like GPX from a running watch, KML from Google Earth, CSVs from your spreadsheets, or TopoJSON files with enhanced geometries. Omnivore makes it all super-simple: omnivore.gpx('run.gpx').addTo(map); Check out examples with GPX, CSV, and KML data.