R help - Nov 2005 - how to draw cumulative histogram

Hello there,

I am using R to plot some cumulative histogram for my data. Please help
in this case.

Thank you

Lisa Wang
Princess Margaret Hospital
Toronto
phone 416 946 4501 ext.4883

I'm not sure what a cumulative histogram is, but does the following help?

x <- rnorm(100)
plot(ecdf(x))

Andy
> From: Lisa Wang
> 
> Hello there,
> 
> I am using R to plot some cumulative histogram for my data. 
> Please help
> in this case.
> 
> Thank you
> 
> Lisa Wang
> Princess Margaret Hospital
> Toronto
> phone 416 946 4501 ext.4883
> 
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>

> I am using R to plot some cumulative histogram for my data. Please help
> in this case.
It's not exactly a cumulative histogram, but perhaps ?ecdf is what you want:
plot(ecdf(islands))

It's also possible to abuse hist to get a cumulative histogram:
h <- hist(islands)
h$counts <- cumsum(h$counts)
plot(h)

(but that was just a quick attempt so may break other code)

Hadley

Selon Lisa Wang <lisawang at uhnres.utoronto.ca>:
> Hello there,
>
> I am using R to plot some cumulative histogram for my data. Please help
> in this case.
>
> Thank you
>
> Lisa Wang
Hi Lisa,

Here is one way (if i am right in what is a cumulative histogram), using the
existing possibilities

cumhist <- function(x, plot=TRUE, ...){
  h <- hist(x, plot=FALSE, ...)
  h$counts <- cumsum(h$counts)
  h$density <- cumsum(h$density)
  h$itensities <- cumsum(h$itensities)

  if(plot)
    plot(h)
  h
}


R> x <- rnorm(100)
R> cumhist(x)
R> # hist(x, add=TRUE, col="cyan")
R> # if you want to overlay the original histogram

-- Romain