%in% returns repeated rows

[vttrifonov]

The %in% operator has an unexpected behavior (see below). I am pretty sure this did not exist before (code which used to work, stopped working, because of this) but I cannot pinpoint the exact time when this happened.

-- example code begins here

library(data.table)

data.table 1.9.4 For help type: ?data.table

*** NB: by=.EACHI is now explicit. See README to restore previous behaviour.

sessionInfo()

R version 3.1.0 (2014-04-10)

Platform: x86_64-unknown-linux-gnu (64-bit)

locale:

[1] C

attached base packages:

[1] stats graphics grDevices utils datasets methods base

other attached packages:

[1] data.table_1.9.4

loaded via a namespace (and not attached):

[1] Rcpp_0.11.2 chron_2.3-45 plyr_1.8.1 reshape2_1.4 stringr_0.6.2

packageVersion("data.table")

[1] '1.9.4'

data.table(a=c(1, 2, 3))[a %in% c(1, 1, 2, 1),]

a

#1: 1
#2: 1
#3: 2
#4: 1

expected to see

a

#1: 1
#2: 2

[arunsrinivasan]

Thanks, but fixed in 1.9.5 (one of the auto indexing bugs).

# v1.9.5
data.table(a=1:3)[a %in% c(1,1,2,1)]
#    a
# 1: 1
# 2: 2