CODEWITHSUNDEEP
rif-statementdata.tablelapply
LeGeniusII
LeGeniusII

Reputation: 960

R data.table use if statement in lapply

I would like to convert some columns from numbers to date format; and I'm thinking about using the following code:

colList <- c("Date1","Date2")
dataDT[, (colList) := lapply(.SD, function(x){
  if (x == 0) {NA}
  else {as.Date(x, origin = "1900-01-01")}
}), .SDcols = colList]

Basically, if the value is 0, then use NA rather than "1900-01-01". Now the problem is:

Warning messages:
1: In if (x == 0) { :
  the condition has length > 1 and only the first element will be used

Is there a way to resolve it?

Upvotes: 0

Views: 723

Answers (2)

Vladimir Volokhonsky
Vladimir Volokhonsky

Reputation: 155

Use "ifelse" instead of "if" in this case:

ifelse (x == 0,NA, as.Date(x, origin = "1900-01-01"))

Upvotes: 2

chinsoon12
chinsoon12

Reputation: 25225

Another option is to use replace:

dataDT[, (colList) := lapply(.SD, 
        function(x) as.Date(replace(x, x==0, NA), origin = "1900-01-01")),
    .SDcols = colList]

Upvotes: 0

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