[R] creating categorical frequency tables from continuous data
saschaview at gmail.com
Thu Jan 27 16:31:52 CET 2011
On 11-01-27 14:58, Louise Mair wrote:
> I am working with a dataset which essentially has only one column - a list of
> distances in metres, accurate to several decimal places. eg
> I want to organise this into a frequency table, grouping into categories of 0
> - 999, 1000 - 1999, 2000-2999 etc. I'd also like the rows where there are no
> data points in that category to contain 0, in order to be able to plot a
> histrogram with a linear x axis, and to statistically analyse differences
> between datasets.
> I have tried table() which doesn't group the data the way I'd like it, I've
> also tried cut() but couldn't make it work. Ideally I'd like the output to
> look something like this...
> distance frequency
> 0-999 0
> 1000-1999 3
> 2000-2999 0
Could be a starting point for testing:
x <- abs(rnorm(500, 5000, 3000)
br <- seq(0, 20000, 1000)
summary(cut(x, br, labels=br[-1], include.lowest=T,
Look at ?cut to find out more. Good luck, *S*
> Any suggestions that are an improvement on doing it manually please?
> Thanks in advance!
> R-help at r-project.org mailing list
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
Sascha Vieweg, saschaview at gmail.com
More information about the R-help