[R] barplot as histogram

Duncan Murdoch murdoch.duncan at gmail.com
Fri Nov 4 19:19:10 CET 2011

On 04/11/2011 2:04 PM, Jesse Brown wrote:
> Hello:
> I'm dealing with an issue currently that I'm not sure the best way to
> approach. I've got a very large (10G+) dataset that I'm trying to create
> a histogram for. I don't seem to be able to use hist directly as I can
> not create an R vector of size greater than 2.2G. I considered
> condensing the data  previous to loading it into R  and just plotting
> the frequencies as a barplot; unfortunately, barplot does not support
> plotting the values according to a set of x-axis positions.
> What I have is something similar to:
> ys<- c(12,3,7,22,10)
> xs<- c(1,30,35,39,60)
> and I'd like the bars (ys) to appear at the positions described by xs. I
> can get this to work on smaller sets by filling zero values in for
> missing ys for the entire range of xs but in my case this would again
> create a vector too large for R.
> Is there another way to use the two vectors to create a simulated
> frequency histogram? Is there a way to create a histogram object (as
> returned by hist) from the condensed data so that plot would handle it
> correctly?

Follow your own last suggestion.  Take a small subset of your data, and 

x <- hist(data, plot=FALSE)

str(x) will show you the structure of the object in x.  Modify the 
entries to reflect your full dataset, and then


will show it.

Duncan Murdoch

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