Add group levels to data frame
114580
How to change the order of facet labels in ggplot (custom facet wrap labels)
52488
Manually setting group colors for ggplot2
39134
Subset data frame based on number of rows per group
61315
Concatenating a column by a group in R
146118
Grouping predictor factor levels based on response variable
144137
Add max value to a new column in R
102653
percentage count by group using dplyr
149518
Adding counts of a factor to a dataframe
147397
How do I combine two data-frames based on two columns?
16381
Include levels of zero count in result of table()
38829
Calculate the mean by group
100039
Annotate grouped bar plot
2060
How do I create group data in a category with more than and less than in R?
58090
Drop unused factor levels in a subsetted data frame
71686
Combine a list of data frames into one data frame by row
146477
pyqgis traversing subgroups and group layers
26241
Add layer to a QGIS group using Python