[R] Looking for the name of a certain kind of quantile plot

Carl Witthoft carl at witthoft.com
Wed Apr 4 00:06:18 CEST 2012


Hi,
While playing with quantile-quantile plots, I wrote up some code which 
plots something strangely different.  Here's the pseudocode:

testhist <- hist(sample_data)
refhist <- hist(rnorm(n, mean=0,sd=1))  # for some large-ish n
cumtest <- cumsum(testhist)
cumref <- cumsum(refhist)

plot(cumref,cumtest)

This produces a straight line of slope 1 for a sample with the same 
parameters as the reference sample, and produces S-curves for samples 
with different sigmas.  A sample with nonzero mean looks almost 
exponential (or logarithmic, depending on the sign of the mean).

So my question is: is there a name for this sort of plot,  and is it of 
any real use in statistical analysis?

thanks.
Carl


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