[Met_help] [rt.rap.ucar.edu #90403] History for point_stat interpolation

[John Halley Gotway via RT]

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  Initial Request
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Hi:

I'm running point_stat using a bi linear interpolation method.  However,
the output messages are confusing me somewhat.  According to the met
documentation, bi linear interpolation, the width should equal 2 (4 data
points).  However, my output looks like this:

DEBUG 2: Processing TMP/Z2 versus air_temperature/Z2, for observation type
MSG001, over region FULL, for interpolation method BILIN(4), using 9 pairs.

What does the "9 pairs" mean here?

Tina

-- 
*************************************************
Christina Kalb
Associate Scientist
National Center for Atmospheric Research
3450 Mitchell Lane
Boulder, CO 80301
kalb at ucar.edu
303-497-2819
*************************************************


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  Complete Ticket History
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Subject: point_stat interpolation
From: Minna Win
Time: Thu May 30 15:35:17 2019

Hi Tina,

John will most likely be able to answer your question, but he is out
of the
office until June 3.  I hope you don't mind waiting a few more days to
have
your question answered.

Thanks,
Minna
---------------
Minna Win
NCAR
Research Applications Lab
Phone: 303-497-8423
Fax:   303-497-8401



On Thu, May 30, 2019 at 9:22 PM Christina Kalb via RT
<met_help at ucar.edu>
wrote:

>
> Thu May 30 15:22:07 2019: Request 90403 was acted upon.
> Transaction: Ticket created by kalb
>        Queue: met_help
>      Subject: point_stat interpolation
>        Owner: Nobody
>   Requestors: kalb at ucar.edu
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=90403 >
>
>
> Hi:
>
> I'm running point_stat using a bi linear interpolation method.
However,
> the output messages are confusing me somewhat.  According to the met
> documentation, bi linear interpolation, the width should equal 2 (4
data
> points).  However, my output looks like this:
>
> DEBUG 2: Processing TMP/Z2 versus air_temperature/Z2, for
observation type
> MSG001, over region FULL, for interpolation method BILIN(4), using 9
pairs.
>
> What does the "9 pairs" mean here?
>
> Tina
>
> --
> *************************************************
> Christina Kalb
> Associate Scientist
> National Center for Atmospheric Research
> 3450 Mitchell Lane
> Boulder, CO 80301
> kalb at ucar.edu
> 303-497-2819
> *************************************************
>
>

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Subject: point_stat interpolation
From: John Halley Gotway
Time: Mon Jun 03 11:36:11 2019

Tina,

I see you have a question about the following Point-Stat log message:

DEBUG 2: Processing TMP/Z2 versus air_temperature/Z2, for observation
type
MSG001, over region FULL, for interpolation method BILIN(4), using 9
pairs.

There is nothing to be concerned about here.  For each verification
task
you request in the config file (where a vx task is a combination of
forecast variable/level, verifying point observation message type,
masking
region, and interpolation method), Point-Stat loops through the point
observations and selects the ones which apply.  In this case, Point-
Stat
found 9 point observations for this vx task based on your
configuration
settings.  So that "9 pairs" means that that's the number of matched
pairs
that will be used in the computation of statistics for this task.

The "BILIN(4)" means that bilinear interpolation is being used.
You're
correct, bilinear interpolation always uses a 2x2 box = 4 grid points.

Thanks,
John

On Thu, May 30, 2019 at 3:44 PM Minna Win via RT <met_help at ucar.edu>
wrote:

>
> Thu May 30 15:43:58 2019: Request 90403 was acted upon.
> Transaction: Given to johnhg (John Halley Gotway) by minnawin
>        Queue: met_help
>      Subject: point_stat interpolation
>        Owner: johnhg
>   Requestors: kalb at ucar.edu
>       Status: open
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=90403 >
>
>
> This transaction appears to have no content
>

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