[R] How is the relation between Frequency and Counts in hist/density defined?
Richard.Cotton at hsl.gov.uk
Richard.Cotton at hsl.gov.uk
Mon May 23 16:56:07 CEST 2011
> In order to do this I can use the relation between count and density, but
I
> would like to know if there is a way for me to predict it upfront.
In the code for hist.default, you'll see the line
dens <- counts/(n * diff(breaks))
> Here is an example:
>
> set.seed(242)
> z = rnorm(30)
> hist_z <- hist(z)
> hist_z$counts / hist_z$density # the relation is 15
In your example, n is 30, and the breaks are evenly spaced every 0.5.
Regards,
Richie.
Mathematical Sciences Unit
[1]HSL
[2]4D Pie Charts
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