АК
> microbenchmark(
+ d[, .(v = sum(f)), by = .(g)],
+ d[, .(v = sum(!f)), by = .(g)]
+ )
Unit: milliseconds
expr min lq mean median uq max neval cld
d[, .(v = sum(f)), by = .(g)] 15.67586 19.76153 26.77643 23.38175 25.29258 158.5116 100 b
d[, .(v = sum(!f)), by = .(g)] 10.70103 11.57647 14.76190 12.19055 14.69412 128.3662 100 a