tab = tabulate

tab prints distinct rows with their count. Compared to the dplyr function count, this command adds frequency, percent, and cumulative percent.

N <- 1e2 ; K = 10
df <- data_frame(
  id = sample(c(NA,1:5), N/K, TRUE),
  v1 = sample(1:5, N/K, TRUE)       
)
tab(df, id)
tab(df, id, na.rm = TRUE)
tab(df, id, v1)

join = merge

join is a wrapper for dplyr merge functionalities, with two added functions