QGis plugins
Some plugins have been developed to make using QGis easier and faster, as part of the Q-traf project. They are not necessary, but can help. They can be downloaded with the Plugins Manager in QGis.
Batch_Csv_Wkt_importer_Fr
http://plugins.qgis.org/plugins/Batch_Csv_Wkt_Importer_Fr/
Allow one to import as many csv files with wkt line geometry, with a single click, provided the files are of the same known type. In this first version, the CRS is by default the CRS of the project, the first field is WKT geometry (and named “WKT”), and all the other fields are of integer type by default. If there are characters in the features, the corresponding field is of string type.
In this Fr version, fields are semicolon separated. A new version of Portable_Q-Traf will use the comma as field separator.
Round_Coordinates
http://plugins.qgis.org/plugins/Round_Coordinates/
Round all the coordinates of a polyline layer / the network to the nearest meter, without decimals.
Show_All_Layers_CRS
http://plugins.qgis.org/plugins/Show_All_Layers_CRS/
Opens a pop-up window listing all the layers with their CRS, name files and number of features.
In a large QGis project with many layers, this helps to identify layers with a different CRS from that of the project, which slows down the whole process. The contents of the pop-up window can be copied/pasted as text.
QGis graphic parameters
These are the parameters to be used for drawing traffic flows.
The graphic parameters of the “traffic_flow_layer” can be download here :
In property > Symbology > Simple Line :
Color line
Color Edit > Edit
Line width :
The width of the line is proportional to the flow (for instance : 100 * “Flow_uvp_pce”). Here’s an example of a little more complicated function which allows to zoom in / out thanks to adding the “@map_scale” parameter of QGis :
Line width > Edit :
Line offset :
The line offset is half the width of the line. So it’s simply the above function, divided by 2 :
Line offset > Edit :
