How can I get the intersection, union, and subset of arrays in Ruby?
I want to create different methods for a class called Multiset. I have all the required methods, but I’m unsure of how to … Read more
subset
Opposite of %in%: exclude rows with values specified in a vector
A categorical variable V1 in a data frame D1 can have values represented by the letters from A to Z. I want to … Read more
How to drop columns by name in a data frame
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 … Read more
Why is `[` better than `subset`?
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 … Read more