Code snippet: subsetting data frame in R by vector

Problem:

you haveto subset a data frame using as criteria the exact match of a vector content.

for instance:

you have a dataset with some attributes, and you have a vector with some values of one of the attributes. You want to make a filter based on the values in the vector.

Example: sales records, each record is a deal.

The vector is a list of selected customers you are interested in.

Is it possible to make such a kind of filter?

Solution

Of course it is!

you just have to use the %in% operator.

let’s see how to do it in the short tutorial here below.

Tutorial

suppose you have a sales data frame object like this:

suppose you want to extract sales to Francesca, Tommaso and Gianna.

first, you have to assign those names to a vector.

vector = c(“Francesca","Tommaso","Gianna")

then, you can write the filtering statement, using the_%in%_operator.

query_result = sales[sales$customer %in% vector,]

and that’s it!

The meaning of _%in%_operator is exactly the one you guess:

“ select only values present INthe specified group”.

Full code is available as an R workbook for quick reference:

filter_code.R

Let me know if you use any other method to obtain the same result.

Finally,if you enjoyed the tutorial, you can find more tutorial on pageTutorial(quite obvious, isnt’ it?).