[Met_help] [rt.rap.ucar.edu #96715] History for ensemble rank

[John Halley Gotway via RT]

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  Initial Request
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Hello,

I am wondering how MET assigns ranks when many ensemble members have the
exact same value?

e.g:
ensembles  value
model 1          5
model 2          6
model 3          6
model 4          7

If obs. is 6, where the obs. should be ranked?

Thank you.
Binyu


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  Complete Ticket History
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Subject: ensemble rank
From: John Halley Gotway
Time: Tue Sep 15 08:00:45 2020

Binyu,

When there are "ties", Ensemble-Stat uses a rank number generator to
randomly select one of the available ranks.

You can see that code which does this starting on this line:
https://github.com/dtcenter/MET/blob/818bb1b6dc769f59a85242e04a213a365df453e4/met/src/libcode/vx_statistics/pair_data_ensemble.cc#L408

Thanks,
John

On Mon, Sep 14, 2020 at 8:43 PM binyu.wang at noaa.gov via RT <
met_help at ucar.edu> wrote:

>
> Mon Sep 14 20:43:26 2020: Request 96715 was acted upon.
> Transaction: Ticket created by binyu.wang at noaa.gov
>        Queue: met_help
>      Subject: ensemble rank
>        Owner: Nobody
>   Requestors: binyu.wang at noaa.gov
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=96715 >
>
>
> Hello,
>
> I am wondering how MET assigns ranks when many ensemble members have
the
> exact same value?
>
> e.g:
> ensembles  value
> model 1          5
> model 2          6
> model 3          6
> model 4          7
>
> If obs. is 6, where the obs. should be ranked?
>
> Thank you.
> Binyu
>
>

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Subject: ensemble rank
From: binyu.wang at noaa.gov
Time: Tue Sep 15 09:48:41 2020

Thank you very much!
Binyu

On Tue, Sep 15, 2020 at 10:00 AM John Halley Gotway via RT <
met_help at ucar.edu> wrote:

> Binyu,
>
> When there are "ties", Ensemble-Stat uses a rank number generator to
> randomly select one of the available ranks.
>
> You can see that code which does this starting on this line:
>
>
https://github.com/dtcenter/MET/blob/818bb1b6dc769f59a85242e04a213a365df453e4/met/src/libcode/vx_statistics/pair_data_ensemble.cc#L408
>
> Thanks,
> John
>
> On Mon, Sep 14, 2020 at 8:43 PM binyu.wang at noaa.gov via RT <
> met_help at ucar.edu> wrote:
>
> >
> > Mon Sep 14 20:43:26 2020: Request 96715 was acted upon.
> > Transaction: Ticket created by binyu.wang at noaa.gov
> >        Queue: met_help
> >      Subject: ensemble rank
> >        Owner: Nobody
> >   Requestors: binyu.wang at noaa.gov
> >       Status: new
> >  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=96715 >
> >
> >
> > Hello,
> >
> > I am wondering how MET assigns ranks when many ensemble members
have the
> > exact same value?
> >
> > e.g:
> > ensembles  value
> > model 1          5
> > model 2          6
> > model 3          6
> > model 4          7
> >
> > If obs. is 6, where the obs. should be ranked?
> >
> > Thank you.
> > Binyu
> >
> >
>
>

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