The NLP Stack

Processing natural language is a complicated business. Not that long ago it seemed to be an intractable problem to many people. Although full understanding is still a cutting edge research problem, large areas of natural language processing have become practical on most computing platforms. This is especially true when NLP techniques are applied to restricted ...

Why Python and NLTK?

Most modern natural language processing (NLP) depends heavily on statistics and complex statistical models. So why use Python,  a relatively slow scripting language,  for NLP? Python’s strengths are in its text, list, and structure support. Structures are weakly typed, but supported by a powerful set of language constructs in the form of list comprehensions and ...

Generating Google Map Heatmap Mashups from your geo-related data

de/numerics have released a web service for creating heatmap translucent color overlays of geographic-based data on Google maps. No programming is required, but this service can be accessed using a PHP API. This article shows you how to use this service using the PHP programming interface.

An Overview of OpenAddresses.org

The aim of OpenAddresses.org is to establish a copyright-free database of geocoded addresses, using donations and voluntary help. Such a database has a wide range of applications including spatial analysis and geomarketing. The database is intended to be of greater accuracy than navigation systems which typically have insufficient accuracy for microgeographic analysis. OpenAddresses includes a ...

Technical Overview: GeoNames

GeoNames is a series of web services to an extensive geographical database of over 8,000,000 names. The database is also available for “bulk” download. Both access methods are under the Creative Commons attribution license. The web services are available through free and commercial interfaces, and using a number of different format/protocols.

Polar Maps and Projections: Part 2, Implementation 2

The first part of this article looked at different ways of producing polar maps and surveyed a number of different azimuthal projections that are often used for polar maps. In this second part, I produce a working implementation using UMN MapServer and OpenLayers.

Polar Maps and Projections: Part 1, Overview

With the success of my earlier series on global equal area map projections (starting with this overview), I received a number of requests to produce a similar how-to article for polar maps. The first part of this article (published here) provides an overview of a number of different map projections commonly used for polar maps. ...

Technical Overview: Geocoder.US

Geocoder.US is a popular online geocoding service. The service supports geocoding through REST, XML-RPC, SOAP, web interface, and email. Limited services are free for non-commercial purposes. Batch geocoding is also available for commercial users.

Technical Overview: Mapstraction

Mapstraction is a JavaScript toolkit that provides an common API to eleven different mapping providers. This allows a developer to create an application that can be easily switched between different base map providers. This could be at development time (eg. if a provider introduces better data) or at runtime (eg. according to region or the ...

How to create an online map with a non-Mercator Projection: Part 2

In the first part of this article we created a WMS server of basemaps using an unconventional map projection (the Mollweide projection). In this second part, we shall implement the client side of the project, creating a working application that will plot user data on the basemaps.