[Met_help] [rt.rap.ucar.edu #79950] History for Regrid output variable names

John Halley Gotway via RT met_help at ucar.edu
Thu Apr 6 08:45:34 MDT 2017


----------------------------------------------------------------
  Initial Request
----------------------------------------------------------------

Hello,

I am trying to use regrid_data_plane to get a collection of GFS grib files
into netCDF. I want to do this for various cloud fraction variables
(column, low, mid, and high). I would like to use the option to include the
-field multiple as to not have to loop through each variable over the valid
date ranges; however, due to the way the output from regrid is saved all
the variables have the same name so it fails. Is there a way to change the
way the variable name is saved?

Thanks,
Mallory Row


----------------------------------------------------------------
  Complete Ticket History
----------------------------------------------------------------

Subject: Regrid output variable names
From: John Halley Gotway
Time: Thu Mar 23 09:26:35 2017

Mallory,

I see that you'd like to regrid several records from GFS GRIB files.
My
first thought is that if you'd really like to regrid many records from
a
GRIB file, I'd suggest using copygb (for GRIB1) or wgrib2 (for GRIB2).
They read/write GRIB files and, by default, process all the records in
the
input file.

The original intention of regrid_data_plane was to provide a stand-
alone
tool to perform the automated regridding that is done by the MET tools
themselves on the fly.  But of course, you're welcome to use it
however
you'd like.  And that's a great point that the "-name" option can only
be
used once to specify a single output name.  That isn't very useful
when
you're using the "-field" option multiple times and would like to
override
regrid_data_plane's default output variable name choice.

It seems to me the desired behavior would be to support a list of "-
name"
settings.  And if "-name" is used, require that the number of names
exactly
matches the number of times "-field" was used.  Then use the first
"name"
for the first "field", second for the second, and so on.

Do you agree?  Would that solve the shortcoming you've found?

Thanks,
John Halley Gotway


On Thu, Mar 23, 2017 at 8:12 AM, Mallory Row - NOAA Affiliate via RT <
met_help at ucar.edu> wrote:

>
> Thu Mar 23 08:12:36 2017: Request 79950 was acted upon.
> Transaction: Ticket created by mallory.row at noaa.gov
>        Queue: met_help
>      Subject: Regrid output variable names
>        Owner: Nobody
>   Requestors: mallory.row at noaa.gov
>       Status: new
>  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=79950 >
>
>
> Hello,
>
> I am trying to use regrid_data_plane to get a collection of GFS grib
files
> into netCDF. I want to do this for various cloud fraction variables
> (column, low, mid, and high). I would like to use the option to
include the
> -field multiple as to not have to loop through each variable over
the valid
> date ranges; however, due to the way the output from regrid is saved
all
> the variables have the same name so it fails. Is there a way to
change the
> way the variable name is saved?
>
> Thanks,
> Mallory Row
>
>

------------------------------------------------
Subject: Regrid output variable names
From: Mallory Row - NOAA Affiliate
Time: Thu Mar 23 11:43:51 2017

Hi John,

Yes, this helps; thank you! I work at EMC and am trying to see how MET
can
fit into our verification here. I'm learning MET as I go in this
process,
but still it is a lot of variables and files that need to be
processed.

Mallory Row

On Thu, Mar 23, 2017 at 11:26 AM, John Halley Gotway via RT <
met_help at ucar.edu> wrote:

> Mallory,
>
> I see that you'd like to regrid several records from GFS GRIB files.
My
> first thought is that if you'd really like to regrid many records
from a
> GRIB file, I'd suggest using copygb (for GRIB1) or wgrib2 (for
GRIB2).
> They read/write GRIB files and, by default, process all the records
in the
> input file.
>
> The original intention of regrid_data_plane was to provide a stand-
alone
> tool to perform the automated regridding that is done by the MET
tools
> themselves on the fly.  But of course, you're welcome to use it
however
> you'd like.  And that's a great point that the "-name" option can
only be
> used once to specify a single output name.  That isn't very useful
when
> you're using the "-field" option multiple times and would like to
override
> regrid_data_plane's default output variable name choice.
>
> It seems to me the desired behavior would be to support a list of "-
name"
> settings.  And if "-name" is used, require that the number of names
exactly
> matches the number of times "-field" was used.  Then use the first
"name"
> for the first "field", second for the second, and so on.
>
> Do you agree?  Would that solve the shortcoming you've found?
>
> Thanks,
> John Halley Gotway
>
>
> On Thu, Mar 23, 2017 at 8:12 AM, Mallory Row - NOAA Affiliate via RT
<
> met_help at ucar.edu> wrote:
>
> >
> > Thu Mar 23 08:12:36 2017: Request 79950 was acted upon.
> > Transaction: Ticket created by mallory.row at noaa.gov
> >        Queue: met_help
> >      Subject: Regrid output variable names
> >        Owner: Nobody
> >   Requestors: mallory.row at noaa.gov
> >       Status: new
> >  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=79950 >
> >
> >
> > Hello,
> >
> > I am trying to use regrid_data_plane to get a collection of GFS
grib
> files
> > into netCDF. I want to do this for various cloud fraction
variables
> > (column, low, mid, and high). I would like to use the option to
include
> the
> > -field multiple as to not have to loop through each variable over
the
> valid
> > date ranges; however, due to the way the output from regrid is
saved all
> > the variables have the same name so it fails. Is there a way to
change
> the
> > way the variable name is saved?
> >
> > Thanks,
> > Mallory Row
> >
> >
>
>

------------------------------------------------
Subject: Regrid output variable names
From: John Halley Gotway
Time: Thu Mar 23 12:49:39 2017

Mallory,

I've added this feature to the upcoming release of MET version 6.0...
for
regrid_data_plane to make "-name" a list of strings for each "-field"
specified.  But yes, using copygb and wgrib2 to regrid entire files is
simpler.

However, there is a little wrinkle to consider.  Generally, it's
advised to
use "budget" interpolation to regrid accumulated variables (like
precip)
and another option (like bilinear) for other data types.  That's not
easy
to do in a single call to copygb.  So we've used wrapper scripts to
split
up GRIB files into the variables for budget and non-budget, call
copygb
twice, and then slap the resulting files back together.  Not sure if
that
detail matters in your work, but wanted to mention it.

Thanks,
John

On Thu, Mar 23, 2017 at 11:43 AM, Mallory Row - NOAA Affiliate via RT
<
met_help at ucar.edu> wrote:

>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=79950 >
>
> Hi John,
>
> Yes, this helps; thank you! I work at EMC and am trying to see how
MET can
> fit into our verification here. I'm learning MET as I go in this
process,
> but still it is a lot of variables and files that need to be
processed.
>
> Mallory Row
>
> On Thu, Mar 23, 2017 at 11:26 AM, John Halley Gotway via RT <
> met_help at ucar.edu> wrote:
>
> > Mallory,
> >
> > I see that you'd like to regrid several records from GFS GRIB
files.  My
> > first thought is that if you'd really like to regrid many records
from a
> > GRIB file, I'd suggest using copygb (for GRIB1) or wgrib2 (for
GRIB2).
> > They read/write GRIB files and, by default, process all the
records in
> the
> > input file.
> >
> > The original intention of regrid_data_plane was to provide a
stand-alone
> > tool to perform the automated regridding that is done by the MET
tools
> > themselves on the fly.  But of course, you're welcome to use it
however
> > you'd like.  And that's a great point that the "-name" option can
only be
> > used once to specify a single output name.  That isn't very useful
when
> > you're using the "-field" option multiple times and would like to
> override
> > regrid_data_plane's default output variable name choice.
> >
> > It seems to me the desired behavior would be to support a list of
"-name"
> > settings.  And if "-name" is used, require that the number of
names
> exactly
> > matches the number of times "-field" was used.  Then use the first
"name"
> > for the first "field", second for the second, and so on.
> >
> > Do you agree?  Would that solve the shortcoming you've found?
> >
> > Thanks,
> > John Halley Gotway
> >
> >
> > On Thu, Mar 23, 2017 at 8:12 AM, Mallory Row - NOAA Affiliate via
RT <
> > met_help at ucar.edu> wrote:
> >
> > >
> > > Thu Mar 23 08:12:36 2017: Request 79950 was acted upon.
> > > Transaction: Ticket created by mallory.row at noaa.gov
> > >        Queue: met_help
> > >      Subject: Regrid output variable names
> > >        Owner: Nobody
> > >   Requestors: mallory.row at noaa.gov
> > >       Status: new
> > >  Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=79950
> >
> > >
> > >
> > > Hello,
> > >
> > > I am trying to use regrid_data_plane to get a collection of GFS
grib
> > files
> > > into netCDF. I want to do this for various cloud fraction
variables
> > > (column, low, mid, and high). I would like to use the option to
include
> > the
> > > -field multiple as to not have to loop through each variable
over the
> > valid
> > > date ranges; however, due to the way the output from regrid is
saved
> all
> > > the variables have the same name so it fails. Is there a way to
change
> > the
> > > way the variable name is saved?
> > >
> > > Thanks,
> > > Mallory Row
> > >
> > >
> >
> >
>
>

------------------------------------------------
Subject: Regrid output variable names
From: John Halley Gotway
Time: Thu Apr 06 08:45:23 2017

Mallory,

I was reviewing open met_help tickets and ran across this one that's
still open.  This enhancement to regrid_data_plane is included in
version 6.0 of MET.

Thanks,
John

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