Generate data.frame from frequency table

Question

I have synthetic data in a 2*4 array with 500 observations:

datax = array(c(120, 181, 50, 43, 41, 33,24,8), dim=c(2,4))
dimnames(datax) = list(gender= c('male', 'female')
                    , punishment = c('None', 'Community_service', 'Youth_prison', 'Normal_prison'))

I'd like to produce a data.frame from the table that represents the "source" of the frequency table.

I can represent it through a "Freq" column (as.data.frame(as.table(datax)), also here) but I'd like to produce the data.frame with 500 rows and 2 columns (gender, punishment).

How would I do this in R?

This is probably a dupe of [this](https://stackoverflow.com/questions/11121385/repeat-rows-of-a-data-frame) — David Arenburg, Feb 20 '19 at 14:10

score 7 · Accepted Answer · answered Feb 20 '19 at 13:55

7

Try this:

long <- as.data.frame.table(datax)
longer <- long[rep(1:nrow(long), long$Freq), -3]

answered Feb 20 '19 at 13:55

G. Grothendieck

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That's exactly it. Fantastic! – ben_aaron Feb 20 '19 at 13:57

Konrad Rudolph · Answer 2 · 2019-02-20T13:57:17.073

1

Using dplyr:

as.data.frame.table(datax) %>%
    rowwise() %>%
    do(data.frame(rep(.$gender, .$Freq), .$punishment))

This constructs a new table for every row in your data, repeating Freq times, and concatenates them into one giant table.

edited Feb 20 '19 at 13:57

answered Feb 20 '19 at 13:52

Konrad Rudolph

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Generate data.frame from frequency table

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