P.S. here's an implementation which satisfies that "Except for the
last interval, each interval is closed on the left and open on the
right." specification:
histogramFixed=: #@[ {. <:@(#/.~)@(i.@#@[ , I.)
Thanks,
--
Raul
On Sat, Apr 10, 2021 at 10:09 AM Raul Miller <[email protected]> wrote:
>
> Here's how I might fix histogram based on Gile's suggestions:
>
> histogram=: (}.~0-0={:)@:<:@(#/.~)@(i.@>:@#@[ , I.)
>
> This is a brute force approach: add an extra tally bucket and discard
> it if it's empty.
>
> But I think that this is not the correct approach. It seems to me that
> there ought to be a test case which illustrates why it is wrong.
>
> Anyways, probably the right place to start is with a clear
> specification of how histogram is supposed to work. And, I am inclined
> to adopt this one:
>
> https://condor.depaul.edu/sjost/it223/documents/histograms.htm
>
> Thoughts?
>
> Thanks,
>
> --
> Raul
>
> On Sat, Apr 10, 2021 at 8:29 AM Brian Schott <[email protected]> wrote:
> >
> > Like Devon, "I have noticed some oddities," and have described my
> > variations at the following link.
> > https://code.jsoftware.com/wiki/User:Brian_Schott/Histogram
> >
> > Below using spacing to emphasize similarities and differences in 3
> > definitions, I have tried to restate the definitions so that a
> > non proportional font will clarify the distinctions.
> >
> > histogram =: <: @ (#/.~) @ (i. @#@[ , I.)
> > histogram1=: <: @ (#/.~) @ (i.@>:@#@[ , I.)
> > histogram2=: <: @ (#/.~) @ (i.@>:@#@[ , Idotr)
> > Idotr =: |.@[ (#@[-I.) ]
> >
> > It seems to me that *histogram1* adjusts for the issue mentioned
> > by Gilles, and *histogram2* further adjusts for the way statisticians
> > traditionally compute histograms with half closed intervals defined as
> > *[,)* instead of *(,]* .
> >
> > Below the verbs are shown with Gilles' data. *histogram1* and
> > *histogram2* place the 0 in different intervals, but at least
> > *histogram1* counts all data.
> >
> > _5 0 5 histogram _2 _7 0 3 9
> > 1 2 1 0
> > _5 0 5 histogram1 _2 _7 0 3 9
> > 1 2 1 1
> > _5 0 5 histogram2 _2 _7 0 3 9
> > 1 1 2 1
> >
> >
> > Btw, the text in the link mentioned above needed to be revised
> > to handle subscripts. Can anyone fix it even further in this regard?
> >
> >
> > --
> > (B=)
> > ----------------------------------------------------------------------
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