CODEWITHSUNDEEP
rdataframemissing-data
Ecg
Ecg

Reputation: 942

Keep only specific strings in a column, otherwise convert to NA

I would like to keep selected strings in a column (A1, B2), and the rest NOT DELETE them, but replace them for NA. I have seen other posts regarding deleting the rows, or partially replacing text, but I would like to replace them with NA, and I cannot find the right command/function.

myDf <- structure(list(GeogPreferences = structure(1:4, .Label = c("A1", 
"B1", "A2", "B2"), class = "factor")), .Names = "Letters", class = "data.frame", row.names = c(NA, -4L))

Not this but something like

keep[, c=("A1", "B2")]
other ways replace with gsub( "non-keep", "NA", as.character(myDf$Letter) n)

Current myDf:

   Letters
1  A1
2  B1
3  A2
4  B2

Desired:

   Letters
1  A1
2  NA
3  NA
4  B2

Upvotes: 0

Views: 264

Answers (1)

jay.sf
jay.sf

Reputation: 72919

This is a job for within.

keep <- c("A2", "B1")
within(myDf, Letters[!Letters %in% keep] <- NA)
#   Letters
# 1    <NA>
# 2      B1
# 3      A2
# 4    <NA>

Upvotes: 2

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