I have recently started using QGIS 3, at a very basic level really, I am displaying radio coverage drive test logs which are in tab delimited format. I have sucessfully imported the file, and written several expressions saved into a 'style' to display the data on a base map with a different coloured spot for each signal level.
Within the log file are entries for 'call start', 'call end', and 'call drop, I have also written expressions to display each of these on the map as a different symbol. If I click on the log file I imported, and select 'show feature count' I am able to see how many calls were started, how many were completed and how many dropped.
What I now want to do is take these totals, perform simple maths on them to create a percentage of successful calls and then display that onto the map alongside the drive test coverage log, in like a title block if you see what I mean.
Would anyone be able to give me some idea of how I would go about that please? I have tried adding a new scratch layer and then I was hoping to write a similar expression to what I already have but to count the number of call start and call end entries but I cannot see how I reference the data from the previously imported coverage log layer .
This is what the imported log file looks like.
Timestamp Longitude Latitude Level Qual EVENT 2018.04.06_09.04.13 -1.138316 52.055508 -92 -10 LOG START 2018.04.06_09.04.13 -1.138316 52.055508 -92 -10 CALL_END 2018.04.06_09.04.13 -1.138316 52.055508 -92 -9 2018.04.06_09.04.15 -1.138316 52.055508 -92 -9 CALL_START 2018.04.06_09.04.22 -1.138316 52.055508 -92 -9 CALL_END 2018.04.06_09.04.24 -1.138316 52.055508 -91 -8 CALL_START 2018.04.06_09.04.31 -1.138316 52.055508 -87 -10 CALL_END 2018.04.06_09.04.34 -1.138316 52.055508 -85 -9 CALL_START 2018.04.06_09.04.41 -1.138316 52.055508 -85 -9 CALL_END
Apologies for the formatting, but each line represents an 'event' and the GPS location and the event which can be call start, call end, call dropped or call blocked. In the example above, I was not moving which is why the Lan / Lon are all the same.