CODEWITHSUNDEEP
rdataframesubset
Dr. Richard Tennen
Dr. Richard Tennen

Reputation: 267

Subset columns in R dataframe issue?

I have a dataframe df that I want to subset in the following way:

Columns 1-7 and a vector of columns cols:

cols = c("rs1057079", "rs1057079.1", "rs4845882", "rs4845882.1", "rs1891932", "rs1891932.1", "rs530296", "rs530296.1", "rs10497340", "rs10497340.1")

So what I did is df[, c(1:7, cols)] but R throws an error:

Error in `[.data.frame`(df, , c(seq(1:7), SNPs_dup)) : 
  undefined columns selected

What is wrong here?? I can subset on 1:7 and cols but why not on both of them?

Upvotes: 0

Views: 73

Answers (1)

akuiper
akuiper

Reputation: 214927

c(1:7, cols) coerces the sequence 1:7 to characters which are further treated as columns names '1', '2' ... instead of column positions, you can extract the 1-7 column names and then concatenate with cols and subset:

df[,c(names(df)[1:7], cols)]

Or convert cols to positions:

df[,c(1:7, match(cols, names(df)))]

Upvotes: 1

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