Stromen weergeven met FlowMapper

This article explains the presentation of flows on a map, using the FlowMapper plugin. For this demonstration, data on commuting patterns between 40 regions are used (from Statistics Netherlands).

Example of FlowMapper output (post-processed)
Example of FlowMapper output (post-processed)

Preparing the data

After the plugin is installed in the usual way, the manual can be found in the folder C:\Users\{username}\.qgis2\python\plugins\FlowMapper2_documentation.Three text files are required, with node coördinates, node names and a flow matrix. Three points must be stressed that are not mentioned in the manual. 1) The plugin does not work well with numbers with decimals. That can be solved by multiplying the numbers by (e.g.) 1000 and then round them. 2) As delimiters, both spaces and tabs may be used. The latter is especially useful when pasting data into a text file from Excel. 3) The node names should not contain spaces, because these are handled as delimiters. Replace them with underscores.
Read More