Do warnings slow down execution in R?-CodePudding

I'm running code in R studio. When my script finishes running, I get the orange message There were 50 or more warnings (use warnings() to see the first 50) at the bottom of my result (and in practice, I suspect the number of warnings is in the tens of thousands, at a minimum). Are these warnings slowing down my code because they're I/O operations and therefore expensive? I'm not seeing any error messages, but I'm not sure if the way R studio handles them, if they're still I/O operations, or if whatever way it's handling them deals with the slowdown I would normally expect such a large number of I/O operations to cause.

CodePudding user response：

Generally, the answer will be yes, code that generates a lot of warnings will have some negative impact on performance although whether this impact is meaningful is going to vary. To illustrate:

library(bench)

v <- -1000:1000

res <- mark(no_warnings = sapply(abs(v), log),
            avoid_warnings = sapply(v, \(x) if (x < 0) NaN else log(x)),
            warnings = sapply(v, log), check = FALSE)

There were 50 or more warnings (use warnings() to see the first 50)

Results:

# A tibble: 3 × 13
  expression          min  median `itr/sec` mem_alloc `gc/sec` n_itr  n_gc total_time
  <bch:expr>     <bch:tm> <bch:t>     <dbl> <bch:byt>    <dbl> <int> <dbl>   <bch:tm>
1 no_warnings     833.6µs  1.06ms     832.     78.9KB     4.23   393     2      472ms
2 avoid_warnings    1.4ms  2.13ms     418.     73.2KB     6.46   194     3      464ms
3 warnings         53.9ms 56.37ms      17.8      64KB     5.08     7     2      394ms
# … with 4 more variables: result <list>, memory <list>, time <list>, gc <list>

plot(res, type = "boxplot")

CodePudding user response：

From my understanding, they will slow it down a bit, although it may be slightly more than marginal at most. However, if you don't need to use the info from the warnings, I suggest avoiding warnings, using something like suppressWarnings()