Within a vector layer I have dissolved 25k polygons into 43 different categories of land ownership (Ld_Use_Des). But now I want to further ''group'' them. For example I want to select Mineral Rights and Recreational and add them to Governmentally_owned (existing category in the attribute table).
2Update the column in question using a conditional expression.– ErikMar 28 at 10:06
do you mean in field calculator?– N_LLCMar 28 at 11:11
Yes, the field calculator is very well capable of doing, what you seem to ask for. You just need to define for yourself, which categories you want to summarize.– ErikMar 28 at 11:57
One way to do this is to run the processing function Statistics by Categories with settings as shown here:
Then export this to a csv field with field ld_use_des the only field that is exported. Then edit this in notepad or excel - add a new category field:
Then add the edited csv file back as a text delimited layer and join it to the original ownership layer using the common field. You can then export that as a new dataset and the categories will be permanently set, or use field calculator to set a new field in the existing layer.
I think there should be a more efficient way in which you stay inside qgis– N_LLCMar 28 at 11:11
1If you have a small number of categories then a conditional expression would be easier but if there are many codes with many categories this way may be quicker. Mar 28 at 11:37
Original post edited with field calculator method Mar 28 at 13:39