IT Nursery
I want to create different methods for a class called Multiset. I have all the required methods, but I’m unsure of how to write intersection, union, and subset methods....
A categorical variable V1 in a data frame D1 can have values represented by the letters from A to Z. I want to create a subset D2, which excludes...
I have a large data set and I would like to read specific columns or drop all the others. data <- read.dta("file.dta") I select the columns that I’m not...
When I need to filter a data.frame, i.e., extract rows that meet certain conditions, I prefer to use the subset function: subset(airquality, Month == 8 & Temp > 90)...