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rtry-catch
Ekat Sim
Ekat Sim

Reputation: 125

Usage of tryCatch function

I would like to use the trycatch function in R to check if the given value is an integer if not return ERROR. My current code looks the following, it doesnt work.

 b <- function() as.integer(n_top_features)
  tryCatch ( {
    error = function(e){
      b()
    }
  },
    stop('ERROR: n_top_features variable should be integer!')
 )

Upvotes: 0

Views: 105

Answers (1)

Konrad Rudolph
Konrad Rudolph

Reputation: 545488

If you read the documentation of the tryCatch function, you see the following usage:

tryCatch(expr, ..., finally)

That is: the actual expression you want to “try” is the first argument, and the handlers (which you’ve attempted to write) come afterwards:

tryCatch(
    as.integer(n_top_features),
    error = function (e) {
        stop('ERROR: n_top_features variable should be integer!')
    }
)

However, that won’t work either; and the reason is that as.integer does not raise an error when the argument can’t be converted to an integer. It raises a warning instead. So your tryCatch needs to install a warning handler:

result = tryCatch(
    as.integer(n_top_features),
    warning = function (w) {
        stop('ERROR: n_top_features variable should be integer!')
    }
)

Upvotes: 3

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