r - Why does data table print inside an if block? -

why happen?

library(data.table) library(plyr)  # revalue  set.seed(123098) my_table <- data.table(x=1:10, str=sample(letters[1:4], 10, replace=t)) my_table[, y := 3*x + runif(nrow(my_table))]  # runs silently  mapping <- c("a"="andrew", "b"="barbarian", "c"="constant", "d"="deft") my_table[, new_str := revalue(str, replace=mapping)]  # runs silently  some_condition <- true if(some_condition) {     my_table[, y := 3*x + runif(nrow(my_table))]  # runs silently     my_table[, new_str := revalue(str, replace=mapping)]  # why print? } 

notice second call new_str := revalue(str, replace=mapping) -- on machine causes data table print. in little example doesn't matter much, have r script operating on large data table, , i'd rather not have unneeded printouts in logs. why happen , how can stop it?

edit: in case helpful:

$ r --version r version 3.0.2 (2013-09-25) -- "frisbee sailing" copyright (c) 2013 r foundation statistical computing platform: x86_64-pc-linux-gnu (64-bit) 

and r session:

> sessioninfo() r version 3.0.2 (2013-09-25) platform: x86_64-pc-linux-gnu (64-bit)  locale:  [1] lc_ctype=en_us.utf-8       lc_numeric=c                [3] lc_time=en_us.utf-8        lc_collate=en_us.utf-8      [5] lc_monetary=en_us.utf-8    lc_messages=en_us.utf-8     [7] lc_paper=en_us.utf-8       lc_name=c                   [9] lc_address=c               lc_telephone=c             [11] lc_measurement=en_us.utf-8 lc_identification=c         attached base packages: [1] stats     graphics  grdevices utils     datasets  methods   base       other attached packages: [1] plyr_1.8.1       data.table_1.9.4  loaded via namespace (and not attached): [1] chron_2.3-45  rcpp_0.11.3   reshape2_1.4  stringr_0.6.2