feature request: math operations on the values

[jhpoosthoek]

Hi, I was wondering if you are considering to add the ability to perform math operations on the values. Example: say your dataset is a set of buildings. For each building you know the total area and the amount of apartments. You also know ownership and building age information. With groupstats you set ownership as the column and building age as the row and you choose as values area and number of apartments. What I would like to show in the spreadsheet is 'area / number of apartments'.

[jhpoosthoek]

I'm trying to code it myself but I have difficulty understanding the code in GroupStatsDialog.py. Could you maybe help me with finding the function/line where I could add code so that the first and second value added to the 'wartosci' object are divided and shown as one value in the generated spreadsheet?

[borysiasty]

Unfortunately the plugin is abandoned by its author, I only updated it to QGIS 3 and have no resources to develop it further.

With all the names and comments in Polish, it would be extremely hard for you to edit the code. Honestly speaking, even for me - a native Polish speaker - it takes long time to find anything there... ;)

The only solution I see would be to find a Polish-speaking developer to either maintain it further or to translate it all to English (the latter sounds great, but it's a huge task, only reasonable with code refactoring to make it more readable). If you wish to sponsor the work, I could try to find someone (there are also Polish support providers on the QGIS.org page - although I guess a freelancer will leave it more "open" ;-) )

[jhpoosthoek]

Thanks for your reply, and the effort you took to update it for QGIS3, it's really a very helpful tool! The tool works great at the moment, but for this particular application I was interested in this added functionality. That's not needed anymore.