r Индекс возврата строк, которые имеют NA в DataFrame
# Basic syntax:
which(is.na(your_dataframe), arr.ind=TRUE)
# Where:
# - which returns the dataframe row indices for rows that contain
# a logical of TRUE
# - is.na processes the dataframe and converts all values to TRUE or
# FALSE based on whether they are NA or not
Charles-Alexandre Roy