根据另一列同一行中的值查找列中的数据

Question

I have a dataframe that has 6 columns (AF) and over 200K rows. I would like to look up a string in a column B (named word), and find its corresponding value in another column D(tf value), same row, please.

For example I want the output to be:

Word: encryption, tf: 0.009041.

I rather not use a loop, but if needed I am open to suggestions, as the df is large. Thank you very much for your time.

Answer 1

It could be that I don't understand the question, but is this what you want?

library(dplyr)
tf <- yourdata %>%
    filter(Word == 'encryption') %>%
    select(tf)

That would create a data frame containing only the column tf and only rows for which the value of Word is 'encryption'. If you wanted the rows containing any one of a set of words in either the columns Class or Word, you could do this:

library(dplyr)
wordset <- c('hockey','encryption')
tf <- yourdata %>%
    filter(Class %in% wordset | Word %in% wordset) %>%
    select(tf)