Here is another double issue of Monthly Maps to begin the new year.

The end of the year saw several great “best maps of 2013″ posts. We will go to them soon but first let’s look at the map that got the “worst map of 2013″ award from Kenneth Field, the Cartonerd. In his famous words, it features a “symposium of technicolour psychedelic vomit across the map.”

cartonerd - worst map of 2013

This beautiful three-dimensional globe-based visualisation of surface wind speed (powered by D3) was featured on both Kenneth Field’s “favourite maps from 2013″ and Wired MapLab’s “the most amazing, beautiful and viral maps of the year” posts.

nullschool.net - earth wind map

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We often find ourselves choosing between various data formats while dealing with spatial data. Consider this (not-so) hypothetical example: your data collection department passed on a bunch of KML files but your analysts insist on SHP files and your web team is very particular about their GeoJSON. If this sounds familiar, you’re reading the right post; we will quickly run through some of the popular vector and raster data formats you should care about and discuss some of the ways to convert data between these formats.

Vector

Shapefiles

The shapefile is perhaps the most popular spatial data format, introduced by Esri.

It is developed and regulated by Esri as a (mostly) open specification for data interoperability among Esri and other GIS software products. – Wikipedia

Esri still has the right to change the format when and if they choose to do so, it is otherwise open and is highly interoperable. Shapefiles can store all the commonly used spatial geometries (points, lines, polygons) along with the attributes to describe these features. Unlike other vector formats, a shapefile comes as a set of three or more files – the mandatory .shp, .shx, .dbf and the optional .prj file The .shp file holds the actual geometries, the .shx is an index which allows you to ‘seek’ the features in the shapefile, the .dbf file stores the attributes and the .prj file specifies the projection the geometries are stored in.
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