I'm new with R. I need to generate a simple Frequency Table (as in books) with cumulative frequency and relative frequency.
So I want to generate from some simple data like
> x
[1] 17 17 17 17 17 17 17 17 16 16 16 16 16 18 18 18 10 12 17 17 17 17 17 17 17 17 16 16 16 16 16 18 18 18 10
[36] 12 15 19 20 22 20 19 19 19
a table like:
frequency cumulative relative
(9.99,11.7] 2 2 0.04545455
(11.7,13.4] 2 4 0.04545455
(13.4,15.1] 1 5 0.02272727
(15.1,16.9] 10 15 0.22727273
(16.9,18.6] 22 37 0.50000000
(18.6,20.3] 6 43 0.13636364
(20.3,22] 1 44 0.02272727
I know it should be simple, but I don't know how.
I got some results using this code:
factorx <- factor(cut(x, breaks=nclass.Sturges(x)))
as.matrix(table(factorx))
You're close! There are a few functions that will make this easy for you, namely cumsum() and prop.table(). Here's how I'd probably put this together. I make some random data, but the point is the same:
#Fake data
x <- sample(10:20, 44, TRUE)
#Your code
factorx <- factor(cut(x, breaks=nclass.Sturges(x)))
#Tabulate and turn into data.frame
xout <- as.data.frame(table(factorx))
#Add cumFreq and proportions
xout <- transform(xout, cumFreq = cumsum(Freq), relative = prop.table(Freq))
#-----
factorx Freq cumFreq relative
1 (9.99,11.4] 11 11 0.25000000
2 (11.4,12.9] 3 14 0.06818182
3 (12.9,14.3] 11 25 0.25000000
4 (14.3,15.7] 2 27 0.04545455
5 (15.7,17.1] 6 33 0.13636364
6 (17.1,18.6] 3 36 0.06818182
7 (18.6,20] 8 44 0.18181818