CODEWITHSUNDEEP
rdataframesubset
Ernie
Ernie

Reputation: 1153

How to subset with empty characters in R?

This one has me tearing my hair out. Suppose I have a data frame like this:

xx <- data.frame(A = c(1,2,3), B = c(4,5,6))
rownames(xx) <- c("p", "q", "r")

This gives:

  A B
p 1 4
q 2 5
r 3 6

I have R code that can result in an empty character (character(0)) that is used to try and subset df xx. If I define a zero character:

z = character(0)

and then I subset xx with:

subset(xx, rownames(xx) != z)

I get:

[1] A B
<0 rows> (or 0-length row.names)

but what I want is the full array, xx, since there is no empty row name. To make this work I have to convert the empty character to and empty string:

z <- ""

Using z <- "", when I subset I get the entire df back, which is what I expect. Explicitly trapping and converting all of these empty characters to empty strings is too clumsy. How to solve this??

Upvotes: 0

Views: 575

Answers (1)

Jake Fisher
Jake Fisher

Reputation: 3310

Try using %in% instead of !=:

subset(xx, !(rownames(xx) %in% z))

Upvotes: 1

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