What is the fastest way to detect if a vector has at least 1 NA in R? I\'ve been using:
sum( is.na( data ) ) > 0
But that
Here are some actual times from my (slow) machine for some of the various methods discussed so far:
x <- runif(1e7)
x[1e4] <- NA
system.time(sum(is.na(x)) > 0)
> system.time(sum(is.na(x)) > 0)
user system elapsed
0.065 0.001 0.065
system.time(any(is.na(x)))
> system.time(any(is.na(x)))
user system elapsed
0.035 0.000 0.034
system.time(match(NA,x))
> system.time(match(NA,x))
user system elapsed
1.824 0.112 1.918
system.time(NA %in% x)
> system.time(NA %in% x)
user system elapsed
1.828 0.115 1.925
system.time(which(is.na(x) == TRUE))
> system.time(which(is.na(x) == TRUE))
user system elapsed
0.099 0.029 0.127
It's not surprising that match and %in% are similar, since %in% is implemented using match.