[ncl-talk] Are recent versions of contributed.ncl backward-compatible?

Thu Feb 2 14:18:32 MST 2017

Hi Daniel,
I think the problem is simply that the name of this variable has been
changed for more recent versions of NCL. I found the file you are
trying to read at ftp.cpc.ncep.noaa.gov. ncl_filedump now reports the
name as TMP_126_HTGL_S123. The name change was made in order to
characterize the last number as representing a statistical processing
method defined in this GRIB1 table:
http://www.nco.ncep.noaa.gov/pmb/docs/on388/table5.html, where 123 is
listed as "Average of N uninitialized analyses, starting at the
reference time, at intervals of P2".
Sorry for the confusion, but particularly with GRIB files, it is
important to recognize that NCL creates these names based on
information in the GRIB file. As the code evolves, occasionally names
have needed to be modified slightly. Anytime you encounter the message
that a variable is not in the file, it is wise to use ncl_filedump to
see if the name actually appears in the file.
 -dave


On Thu, Feb 2, 2017 at 1:46 PM, Daniel Barandiaran - NOAA Affiliate
<daniel.barandiaran at noaa.gov> wrote:
> Here is the relevant code for the problem with the GRIB read:
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
> f =addfile("/cpc/home/ebecker/ghcn_cams/ghcn_cams_1948_cur_t126.grb","r")
> TIME  = cd_calendar(f->initial_time0_hours,0)
> inntime     = dimsizes(TIME(:,0))
> inyrmin     = 1981
> inyrmax     = toint(datmaxyr)
> innyr = inyrmax - inyrmin + 3
> ntime = innyr * 12
> tind  := ind(TIME(:,0).ge.inyrmin)
>
> year  = fspan(inyrmin,inyrmax+2,innyr)
> year!0      = "year"
> year&year   = year
>
> time  = fspan(0,ntime-1,ntime)
> time!0      = "time"
> time&time   = time
> time at units  = "months since 1981-01-01 00:00:00"
> delete(TIME)
> TIME  = cd_calendar(time,0)
>
> lat   = f->lat_126({minlat:maxlat})
> nlat  = dimsizes(lat)
> lon   = f->lon_126({minlon:maxlon})
> nlon  = dimsizes(lon)
>
> lat!0 = "lat"
> lat&lat     = lat
> lat at units   = "degrees_north"
>
> lon!0 = "lon"
> lon&lon     = lon
> lon at units   = "degrees_east"
>
> tin   = f->TMP_126_HTGL_123(tind,{minlat:maxlat},{minlon:maxlon})
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
> And the error code that comes out:
>
> fatal:["Execute.c":6332]:variable (TMP_126_HTGL_123) is not in file (f)
>
> fatal:["Execute.c":8575]:Execute: Error occurred at or near line 163 in file
> tmp_cv_fcst_namer.ncl
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
>
> This script works fine in 6.1.2, and the variable name is given explicitly
> rather than using a GRIB table.
>
>
> On Thu, Feb 2, 2017 at 3:23 PM, Mary Haley <haley at ucar.edu> wrote:
>>
>> Hi Daniel,
>>
>> Unfortunately you won't be able to point to a 6.3.0 contributed.ncl while
>> using a 6.1.2 "ncl", because it is very likely that contributed.ncl is
>> depending on a new built-in function that's only available in the 6.3.0 ncl
>> executable.
>>
>> We should try to figure out why you can't open your GRIB file with 6.3.0.
>> We try *very hard* to be backwards compatible, but sometimes with GRIB
>> files, there are things we have to change, usually having to do with
>> variable names. I don't know if that's what's happening in your case.
>>
>> Are you getting an error? It would be helpful if we could see it.
>>
>> Also in NCL V6.2.0, which was released between 6.1.2 and 6.3.0, there were
>> some updates to the GRIB reader. Maybe this update is affecting you? You can
>> read more about these updates at:
>>
>> http://www.ncl.ucar.edu/prev_releases.shtml#FileIOImprovements6.2.0
>>
>> Also, you might want to read the "file I/O improvements" section of our
>> 6.3.0 release notes:
>>
>> http://www.ncl.ucar.edu/current_release.shtml#Improvements6.3.0
>>
>> --Mary
>>
>>
>> On Thu, Feb 2, 2017 at 12:17 PM, Daniel Barandiaran - NOAA Affiliate
>> <daniel.barandiaran at noaa.gov> wrote:
>>>
>>> It seems a little strange to me as well, but the bottom line is that I
>>> could open the GRIB file no problem using the 6.1.2 installed on our server,
>>> but could not using my test-install of 6.3.0. Paths in our machine are
>>> preset, and I'm not even sure exactly where they all point to. In order to
>>> ensure I was running the test install I put an alias in my .bashrc, and I
>>> made sure to set $NCAR_ROOT to point to the test install as well.
>>>
>>> On Thu, Feb 2, 2017 at 2:03 PM, Guido Cioni <guidocioni at gmail.com> wrote:
>>>>
>>>> Hey Daniel,
>>>> I’m sure that someone will be more useful than me but…aren’t GRIB
>>>> library supposed to be independent from NCL?
>>>> Maybe there is something wrong on GRIB API and not on the installation
>>>> of NCL, or maybe you didn’t set the GRIB_API path properly? Just saying,
>>>> don’t know whether it is relevant or not :)
>>>>
>>>> Cheers
>>>>
>>>> Il giorno 02 feb 2017, alle ore 19:13, Daniel Barandiaran - NOAA
>>>> Affiliate <daniel.barandiaran at noaa.gov> ha scritto:
>>>>
>>>> Our work machine here at CPC is running ncl-6.1.2. I requested an update
>>>> and got turned down by the IT folks; their reason had something to do with
>>>> old netCDF packages and an eventual upgrade of our Linux environment, at
>>>> which time it would be easier to upgrade. In the meantime I tried to unpack
>>>> the latest binaries into my personal work directory and set paths
>>>> appropriately, but sure enough there were some serious problems, like not
>>>> being able to read variables out of a GRIB file. I have therefore mostly
>>>> resigned myself to working with 6.1.2, but this morning I thought that a lot
>>>> of the functions I am pining for reside in contributed.ncl, so I was
>>>> wondering if I could point to the contributed.ncl that came with 6.3.0 while
>>>> still running 6.1.2? And what about the ESMF regridding, could I point to
>>>> the ESMF_regridding.ncl script and use those functions as well?
>>>>
>>>> --
>>>> Danny Barandiaran, Ph.D.
>>>> Contract Scientist-INNOVIM
>>>> Climate Prediction Center/NCEP/NWS, W/NP5
>>>> National Center for Weather and Climate Prediction
>>>>
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>>>>
>>>
>>>
>>>
>>> --
>>> Danny Barandiaran, Ph.D.
>>> Contract Scientist-INNOVIM
>>> Climate Prediction Center/NCEP/NWS, W/NP5
>>> National Center for Weather and Climate Prediction
>>>
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> ncl-talk at ucar.edu
>>> List instructions, subscriber options, unsubscribe:
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>>>
>>
>
>
>
> --
> Danny Barandiaran, Ph.D.
> Contract Scientist-INNOVIM
> Climate Prediction Center/NCEP/NWS, W/NP5
> National Center for Weather and Climate Prediction
>
>
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