Using logical operators to subset in a function

Question

I'm trying to use a logical operator to subset in a function as follows:

iris$Species <- as.character(iris$Species)

mySubsetFunction <- function(df, species){
  dfSubset <- subset(df, Species==species)
  return(dfSubset)
}

mySubsetFunction(iris, species="setosa" | species="virginica")

This returns an error:

Error: unexpected '=' in "mySubsetFunction(iris, species="setosa" | species="

How can I set up the arguments of the function to accept logical operators?

score 4 · Accepted Answer · edited May 23 '17 at 12:18

You meant to either do:

mySubsetFunction <- function(df, species){
    dfSubset <- subset(df, Species %in% species)
    return(dfSubset)
}

mySubsetFunction(iris, c("setosa", "virginica"))

(However, use caution when using subset inside functions: Why is `[` better than `subset`?)

Or use subset directly:

subset(iris, Species == "setosa" | Species == "virginica"`)

or

subset(iris, Species %in% c("setosa", "virginica"))

Using logical operators to subset in a function

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