[R] histograms

[Kurt Hornik]

>>>>> D A Wooff writes:

>> >>>>> "PD" == Peter Dalgaard BSA <p.dalgaard at biostat.ku.dk> writes:
>> 
PD> "Venables, Bill (CMIS, Cleveland)" <Bill.Venables at cmis.CSIRO.AU>
PD> writes:
>> >> The fact that every elementary book on statistics does it this way
>> >> does not make it correct.  To be helpful, a histogram really has to
>> >> be a non-parametric density estimator, period.
>> >> 
>> >> Enough already of polemics.
>> 
PD> Not quite! There is a reason for doing it the other way, namely
PD> that the concept of a histogram generally comes before the concept
PD> of a probability density, pedagogically. It is very easy to explain
PD> that you chop up the axis into bins and count the number of data
PD> points that fall in each of them. I bet that half of the MDs that I
PD> teach never quite understand the density (hell, the author of the
PD> textbook I use managed to plot three identical gaussian curves with
PD> identical y axis but different x axes... and he's a
PD> statistician). So for the basic uses of the histogram, one would be
PD> replacing a perfectly intuitive simple unit with a substantially
PD> more complex one.
>> 
>> I agree 100% with Peter.  
>> Being a mathematician I agree with Bill that for us, a histogram is a
>> (very suboptimal) density estimate;  but average statistics software users
>> *do* learn histograms differently..  

> I hope there are many of us that agree 100% with Bill. Bad practice,
> as enshrined in the default behaviour of histogram, should be
> discouraged.  We should aim to introduce density-based histograms from
> the outset, and the default behaviour of histograms in many packages
> acts against this principle. The current default behaviour conveys a
> misleading and arguably useless summary, and I don't go with the
> argument that we should persist with it because it is simple to
> understand where the numbers come from.

I side with Peter.  In an elementary stats course ...

Maybe have densityplot(..., method = "histogram") for the real thing?

-k

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