This is the second post on maps in Qlikview using streaming maps from Idevio. The first post covered the basic functionality. This post shows one example how lines can be used to visualize relations between objects. The IdevioMaps extension can also render other objects such as symbols and regions using fast, vector-based, streaming maps.
Lines can be very useful to describe relations between objects, one typical example is track lines, where the lines connect observations of the same object at different times. Below is a screenshot from our demo based on data from the boat race Volvo Ocean Race 2005, leg 8 and 9.
The lines are defined by a column that contains the boat id and the map connects the boat positions into a continuous line in chronological order. In this example one line per boat is displayed, the width and color of the line are controlled by expressions.
IdevioMaps supports a second mode of line rendering, centric lines, where lines are drawn from the object to a center point. The example below shows delay statistics for Ryanair flights from UK in 2010, the data comes from FlightOnTime.info. The map is rotated to make room for more lines. The light purple line describes flights more than 3 hours delayed and the darker purple line describes flights more than 1 hour delayed.
The lines are defined using a column with references to center points. The center points are in the selection in order for lines to be rendered. In this example two lines with color and width are used, the thinnest line are always placed on top. Line widths are in the same y scale. Lines are not drawn if the expressions for widths are nil or if the line id is the same as the point id.
Idevio specialize in hi-performance map engines for defense and industry, and we are a technology partner of Qliktech since 2009. Idevio is a Swedish company and our partners and customers include Ericsson, Logica, Schenker, Thales, Active Professionals BV, the Swedish Armed Forces and G4S. We provide mapping, geocoding and routing services and software for web, mobile and embedded devices.
Please contact me directly if you want to try the extension, there are also web based Qlikview demos available at www.idevio.com/demo.
Patric Nordström, Idevio +46 31 779 09 60