subset()

subset()

subset(df, condition) filters a data frame's rows based on a logical condition, similar to a SQL WHERE clause. It also accepts a select argument to choose specific columns at the same time. subset() is a convenient shorthand over the more verbose df[df$col > x, ] indexing syntax.

Note: subset()'s condition can reference column names directly, without needing df$ prefixes, unlike standard bracket indexing.

Example: subset()

df <- data.frame(name = c("Alice", "Bob", "Cara"), age = c(30, 25, 40))

adults <- subset(df, age >= 30)
print(adults)

names_only <- subset(df, age >= 30, select = name)
print(names_only)