[Met_help] [rt.rap.ucar.edu #94829] History for gen_vx_mask longitude specification
John Halley Gotway via RT
met_help at ucar.edu
Mon Apr 27 17:34:21 MDT 2020
----------------------------------------------------------------
Initial Request
----------------------------------------------------------------
Folks - I am wondering what the E/W conversion for longitudes is for input to gen_vx_mask.
Efren A. Serra (Contractor)
Physicist
DeVine Consulting, Inc.
Naval Research Laboratory
Marine Meteorology Division
7 Grace Hopper Ave., STOP 2
Monterey, CA 93943
Code 7542
Mobile: 408-425-5027
----------------------------------------------------------------
Complete Ticket History
----------------------------------------------------------------
Subject: gen_vx_mask longitude specification
From: John Halley Gotway
Time: Fri Apr 03 17:33:31 2020
Efran,
I see you have a question about the conventions for longitudes in MET.
MET
expects all input longitudes to follow the standard convention of
"degrees
east", meaning east of lon 0 is positive.
If you look into the code you'll see that after reading longitude
values,
it does multiply them by -1 to convert from degrees east to west. Our
internal grid library expects that. However, we do convert them back
to
degrees east when writing longitudes to output files. I'd really like
to
update our grid library to follow the degrees east convention to avoid
all
that multiplying -1. But for the time being, that's what we've got.
Hope that helps clarify.
Thanks,
John Halley Gotway
On Fri, Apr 3, 2020 at 1:54 PM efren.serra.ctr at nrlmry.navy.mil via RT
<
met_help at ucar.edu> wrote:
>
> Fri Apr 03 13:54:38 2020: Request 94829 was acted upon.
> Transaction: Ticket created by efren.serra.ctr at nrlmry.navy.mil
> Queue: met_help
> Subject: gen_vx_mask longitude specification
> Owner: Nobody
> Requestors: efren.serra.ctr at nrlmry.navy.mil
> Status: new
> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=94829 >
>
>
> Folks - I am wondering what the E/W conversion for longitudes is for
input
> to gen_vx_mask.
>
> Efren A. Serra (Contractor)
> Physicist
>
> DeVine Consulting, Inc.
> Naval Research Laboratory
> Marine Meteorology Division
> 7 Grace Hopper Ave., STOP 2
> Monterey, CA 93943
> Code 7542
> Mobile: 408-425-5027
>
>
>
------------------------------------------------
Subject: RE: [rt.rap.ucar.edu #94829] gen_vx_mask longitude specification
From: efren.serra.ctr at nrlmry.navy.mil
Time: Fri Apr 03 18:24:22 2020
Here's how I'm parsing longitudes from ATCF objective aids files and
before I pass them to gen_vx_mask:
def parse_lon(s):
lon=float(s[:-1])*0.1
if s[-1] == "W":
lon = 360.0 - lon
# MET tools convention
return round(lon)
Is this the correct conversion?
-----Original Message-----
From: John Halley Gotway via RT <met_help at ucar.edu>
Sent: Friday, April 3, 2020 4:34 PM
To: Serra, Mr. Efren, Contractor, Code 7531
<efren.serra.ctr at nrlmry.navy.mil>
Subject: Re: [rt.rap.ucar.edu #94829] gen_vx_mask longitude
specification
Efran,
I see you have a question about the conventions for longitudes in MET.
MET expects all input longitudes to follow the standard convention of
"degrees east", meaning east of lon 0 is positive.
If you look into the code you'll see that after reading longitude
values, it does multiply them by -1 to convert from degrees east to
west. Our internal grid library expects that. However, we do convert
them back to degrees east when writing longitudes to output files.
I'd really like to update our grid library to follow the degrees east
convention to avoid all that multiplying -1. But for the time being,
that's what we've got.
Hope that helps clarify.
Thanks,
John Halley Gotway
On Fri, Apr 3, 2020 at 1:54 PM efren.serra.ctr at nrlmry.navy.mil via RT
< met_help at ucar.edu> wrote:
>
> Fri Apr 03 13:54:38 2020: Request 94829 was acted upon.
> Transaction: Ticket created by efren.serra.ctr at nrlmry.navy.mil
> Queue: met_help
> Subject: gen_vx_mask longitude specification
> Owner: Nobody
> Requestors: efren.serra.ctr at nrlmry.navy.mil
> Status: new
> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=94829
> >
>
>
> Folks - I am wondering what the E/W conversion for longitudes is for
> input to gen_vx_mask.
>
> Efren A. Serra (Contractor)
> Physicist
>
> DeVine Consulting, Inc.
> Naval Research Laboratory
> Marine Meteorology Division
> 7 Grace Hopper Ave., STOP 2
> Monterey, CA 93943
> Code 7542
> Mobile: 408-425-5027
>
>
>
------------------------------------------------
Subject: RE: [rt.rap.ucar.edu #94829] gen_vx_mask longitude specification
From: efren.serra.ctr at nrlmry.navy.mil
Time: Fri Apr 03 19:05:18 2020
John,
Let's say I give you this longitudes:
408W
434W
460W
483W
504W
535W
569W
613W
662W
655W
651W
631W
How would you convert them, after multiplying the integer part by 0.1,
for input to gen_vx_mask? Thank you.
-----Original Message-----
From: John Halley Gotway via RT <met_help at ucar.edu>
Sent: Friday, April 3, 2020 4:34 PM
To: Serra, Mr. Efren, Contractor, Code 7531
<efren.serra.ctr at nrlmry.navy.mil>
Subject: Re: [rt.rap.ucar.edu #94829] gen_vx_mask longitude
specification
Efran,
I see you have a question about the conventions for longitudes in MET.
MET expects all input longitudes to follow the standard convention of
"degrees east", meaning east of lon 0 is positive.
If you look into the code you'll see that after reading longitude
values, it does multiply them by -1 to convert from degrees east to
west. Our internal grid library expects that. However, we do convert
them back to degrees east when writing longitudes to output files.
I'd really like to update our grid library to follow the degrees east
convention to avoid all that multiplying -1. But for the time being,
that's what we've got.
Hope that helps clarify.
Thanks,
John Halley Gotway
On Fri, Apr 3, 2020 at 1:54 PM efren.serra.ctr at nrlmry.navy.mil via RT
< met_help at ucar.edu> wrote:
>
> Fri Apr 03 13:54:38 2020: Request 94829 was acted upon.
> Transaction: Ticket created by efren.serra.ctr at nrlmry.navy.mil
> Queue: met_help
> Subject: gen_vx_mask longitude specification
> Owner: Nobody
> Requestors: efren.serra.ctr at nrlmry.navy.mil
> Status: new
> Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=94829
> >
>
>
> Folks - I am wondering what the E/W conversion for longitudes is for
> input to gen_vx_mask.
>
> Efren A. Serra (Contractor)
> Physicist
>
> DeVine Consulting, Inc.
> Naval Research Laboratory
> Marine Meteorology Division
> 7 Grace Hopper Ave., STOP 2
> Monterey, CA 93943
> Code 7542
> Mobile: 408-425-5027
>
>
>
------------------------------------------------
Subject: gen_vx_mask longitude specification
From: John Halley Gotway
Time: Fri Apr 03 20:25:39 2020
Efren,
Here’s an example polyline containing lat/Lin points:
https://github.com/NCAR/MET/blob/master_v9.0/met/data/poly/CONUS.poly
If you have degrees west, just multiply by -1 to put them into degrees
East. If you’d like, you can also add/subtract by 360 degrees to put
them
in whatever range you prefer. MET automatically does that as it reads
them
to put them into a standard range of (-180,180).
John
On Fri, Apr 3, 2020 at 7:05 PM efren.serra.ctr at nrlmry.navy.mil via RT
<
met_help at ucar.edu> wrote:
>
> <URL: https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=94829 >
>
> John,
>
> Let's say I give you this longitudes:
> 408W
> 434W
> 460W
> 483W
> 504W
> 535W
> 569W
> 613W
> 662W
> 655W
> 651W
> 631W
>
> How would you convert them, after multiplying the integer part by
0.1, for
> input to gen_vx_mask? Thank you.
>
> -----Original Message-----
> From: John Halley Gotway via RT <met_help at ucar.edu>
> Sent: Friday, April 3, 2020 4:34 PM
> To: Serra, Mr. Efren, Contractor, Code 7531 <
> efren.serra.ctr at nrlmry.navy.mil>
> Subject: Re: [rt.rap.ucar.edu #94829] gen_vx_mask longitude
specification
>
> Efran,
>
> I see you have a question about the conventions for longitudes in
MET.
> MET expects all input longitudes to follow the standard convention
of
> "degrees east", meaning east of lon 0 is positive.
>
> If you look into the code you'll see that after reading longitude
values,
> it does multiply them by -1 to convert from degrees east to west.
Our
> internal grid library expects that. However, we do convert them
back to
> degrees east when writing longitudes to output files. I'd really
like to
> update our grid library to follow the degrees east convention to
avoid all
> that multiplying -1. But for the time being, that's what we've got.
>
> Hope that helps clarify.
>
> Thanks,
> John Halley Gotway
>
> On Fri, Apr 3, 2020 at 1:54 PM efren.serra.ctr at nrlmry.navy.mil via
RT <
> met_help at ucar.edu> wrote:
>
> >
> > Fri Apr 03 13:54:38 2020: Request 94829 was acted upon.
> > Transaction: Ticket created by efren.serra.ctr at nrlmry.navy.mil
> > Queue: met_help
> > Subject: gen_vx_mask longitude specification
> > Owner: Nobody
> > Requestors: efren.serra.ctr at nrlmry.navy.mil
> > Status: new
> > Ticket <URL:
https://rt.rap.ucar.edu/rt/Ticket/Display.html?id=94829
> > >
> >
> >
> > Folks - I am wondering what the E/W conversion for longitudes is
for
> > input to gen_vx_mask.
> >
> > Efren A. Serra (Contractor)
> > Physicist
> >
> > DeVine Consulting, Inc.
> > Naval Research L
>
<https://www.google.com/maps/search/%3E+Naval+Research+L?entry=gmail&source=g>
> aboratory
> > Marine Meteorology Division
> > 7 Grace Hopper Ave., STOP 2
> > Monterey, CA 93943
> > Code 7542
> > Mobile: 408-425-5027
> >
> >
> >
>
>
>
>
------------------------------------------------
More information about the Met_help
mailing list