R - fastest way to detect if vector has at least 1 NA? -


wondering fastest way detect if vector has @ least 1 na? i've been using:
sum( is.na( data ) ) > 0
requires examining each element, coercion , , sum function.

the newer versions of r have anyna() option. on atomic vectors stop after first na instead of going through entire vector case any(is.na()). borrowing joran's example:

x <- y <- runif(1e7) x[1e4] <- na y[1e7] <- na microbenchmark::microbenchmark(any(is.na(x)), anyna(x), any(is.na(y)), anyna(y), times=10) # unit: microseconds #           expr        min         lq        mean      median         uq #  any(is.na(x))  13444.674  13509.454  21191.9025  13639.3065  13917.592 #       anyna(x)      6.840     13.187     13.5283     14.1705     14.774 #  any(is.na(y)) 165030.942 168258.159 178954.6499 169966.1440 197591.168 #       anyna(y)   7193.784   7285.107   7694.1785   7497.9265   7865.064

notice how substantially faster when modify last value of vector. big part of savings, in addition stopping early, don't need create , allocate memory entire logical vector size of our numeric vector.


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