So I’ve been promising an update to my Timemap series so here is the next stage of tinkering.
This is based on a live demo I did at the first UK QGIS User Group a few weeks ago and is a result of looking at multi-level data within the same time period. Again, I’ve used railways as the basis, simply because I love railways and loving a subject spurs you on when you’re completing what can be, repetitive tasks.
So the first thing is to set up your basic route [or series], mine is the line between Bletchley and Bedford St. Johns.
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First thing to mention is that this is created in QGIS 1.8 as the plugin for version 2.0 wasn’t ready.
The line was split into 32 sections (see picture), as it takes 32 minutes to travel between the stations, but you will determine the frequency based on your own time requirements.
- It is important to make sure you create your records in a sequential manner as the plugin goes through record by record.
- Each record is given a start and end time (end time not required) – the format of the date/time is important, look at the plugin to determine how you want to format this but make sure you change it in the settings within the plugin else it just won’t work! I tend to keep to the default setting yyyy-mm-dd hh:mm:ss (you can see how the table is made up from my previous post).
- I also created a table of points for the stations, with the same structure as the route but a column added which holds the name of the station. This column is used to label the station. The point symbols were made to be 100% transparent so they don’t show but were set to be labelled with their name – you don’t have to do this but I only wanted the names to show as the train went by (as it were).
- Set the start time for each station to correspond with the line segment just preceding it and the end time to however long you want the label to appear (no end time will result in the label staying visible until the end of the whole animation).
- In the plugin add all the tables you require and run it!
That’s it really, simple to do but attention to the detail and format are key to making it work.
You can see the finished video here: http://youtu.be/mirKr5cSf_I
You are not bound by lines, any object can be made to appear/disappear if it has a date/time – I showed an example of random circles with labels containing information so as long as there’s a temporal aspect to data it will work but better still, it will impress in terms of communicating information.