|Something a bit more advanced: Displaying statistical data in 3D |
| ||One of the strengths in using GIS and mapping for analytical capabilities is the power of visualisation. We all love the thematic maps, but another interesting method is to use grids to visualise numeric data in the same way that you would visualise a digital elevation model. This method is also useful when you need to visualize a combination of numeric values. |
In this example we use standard demographic data from Statistics Sweden showing population in 5-year intervals for male, female and the total population.
A browser window showing a small portion of the table
Grids are 1km in rural areas and 250 meters in urban areas, and we are using StreetPro Sweden for the background map.
Grids overlayed on a StreetPro map zoomed in on Stockholm. StreetPro map is © TomTom BV
Let us say we are analysing the amount of people in the range 20-29 years. We can do this with a thematic map. In this example we apply an expression to calculate the amount and round the result to the nearest percent.
We make the thematic layer 40% transparent so the background map is still visible, this facilitates map navigation.
A traditional thematic map from demographic data
To display the demographic data in 3D we will use Engage 3D Pro, which has the capabilities to create and display grids in a map, as well as display grids and maps in a separate 3D window. To create the grid we first need to add a column to the table and update this column. In this case we want to visualize the total number of people in the age 20-29 years, so we add this to the table.
Update column: Adding two columns together.
In the Surfaces menu we can now create a grid using the demographic data as input. The numeric data in the demographic squares will be treated as points representing the centre of each square. In this case we use the interpolation method Spatial Neighbour and the default colour settings.
Interactive gridding dialogue
The grid will be added to the map below the existing layers, as it is treated as a raster layer. This is fine as we have no interest in displaying the grid in the map. Instead we go to the Engage 3D menu and select the option View map in 3D. We select the map window and the newly created grid, and voilÃ - the map is displayed in 3D where peaks show the amount of people aged 20-29, and the thematic colouring shows the percentage of people in this age.
The peak in the upper right is located at the main campus of Stockholm University
Editors note: The techniques in this article used both the MapInfo Professional and Engage 3D Pro products. For more information on Engage 3D, visit our Web site here for more!
Article by Håkan Karlsson, Senior Systems Engineer
When not writing articles for the MapInfo Professional, Håkan is devoted to understand the current challenges of our partners and their customers. Håkan recently bought a summer house outside Stockholm and is now practicing scything, resulting in some small success and some large blisters.