[ncl-talk] setfileoption("h5" ...

[Dennis Shea]

Hi Laura

I may be wrong about NCL's standard variable & file structures but I am
pretty sure it is based on the classic netCDF-3 file and variable models.

[a]
There is no concept of multiple levels of data. netCDF-3 files are 'flat.'
To accommodate this 'flat' nature, all variable names must be unique.

[b]
HDF5/netCDF4 allow multiple levels [eg: 'groups'].  A variable [eg: FOO]
can exist in several groups with the same name and refer to completely
different quantities.

---

>From setfileoption

"In version *6.1.1*, this option only has an effect for classic model
NetCDF files (including NetCDF4 classic files). But other than the
difference in print output, there should be no difference in the way
classic model NetCDF is read or written, regardless of the file structure.

However, beginning with version 6.2.0
<http://www.ncl.ucar.edu/prev_releases.shtml#6.2.0>, this option will work
for HDF-EOS5 and shapefiles. Choosing the *"Advanced"* file structure will
allow the user to *view these file formats using a representation closer to
the structure implied by the native format.* Conversely, the *"Standard"*
structure will remain available to let you to view the contents as you
alway have; in other words backwards compatibility is maintained.
Eventually other supported formats that can make ues of the advanced
features, including HDF4 and HDFEOS2, may also be enabled to use the
*"Advanced"* file structure.

[Further ...]

Like full model NetCDF4, HDF5 will be implemented using the *"Advanced"*
file structure only."

The above should read:

Like full model NetCDF4, HDF5 will be *automatically* implemented using the
*"Advanced"* file structure only."

&&&&&&&&&&&&&

There is a GPM example at:

https://www.ncl.ucar.edu/Applications/HiResPrc.shtml

gpm_1.ncl <https://www.ncl.ucar.edu/Applications/Scripts/gpm_1.ncl>

&&&&&&&&&&&&&
I think there is something wrong with the file you ftp'd:

%> ncl_filedump  3A-MO.GPM.DPR.V2-20170217.20151201-S000000-E235959.12.
V05A.HDF5

 Copyright (C) 1995-2017 - All Rights Reserved
 University Corporation for Atmospheric Research
 NCAR Command Language Version 6.5.0 -29Mar2018_0148
 The use of this software is governed by a License Agreement.
 See http://www.ncl.ucar.edu/ for more details.
Assertion failed: (0), function NC4_open, file nc4file.c, line 2874.
Abort

-----

%> ncdump -k* 3A*-MO.GPM.DPR.V2-20170217.20151201-S000000-E235959.12.
V05A.HDF5

Assertion failed: (0), function NC4_open, file nc4file.c, line 2874.

-----

To illustrate that 'ncdump -k'  works, I have used it on a  different GPM
file:

%> ncdump -k *3B-*MO.MS.MRG.3IMERG.20140312-S000000-E235959.03.V03D.HDF5




*netCDF-4-----*



*For NCL-core developres, the file is at:/glade/p/ncldev/data/gpm*




On Tue, May 22, 2018 at 2:19 PM, Laura Fowler <laura at ucar.edu> wrote:

> Hello:
> Just a couple of quick questions:
>
>
> 1. I am reading an HDF5 file containing GPM data and I was wondering
> if there was a description of the command:
> setfileoption("h5","FileStructure","Advanced")
>
> In the online documentation, I found that setfileoption is described
> for netCDF and GRIB, but not for HDF5?
>
>
> 2. I read the HDF5 file and define the group g2 as:
>
> g2 = f=>/Grids/G2
> mean   = g2->precipRateNearSurfaceUnconditional
> .
> .
> .
>
> After I plot the variable mean, I am trying to open an other group g2 as:
> ichn = 3
> g2 = f=>/Grids/G2/precipRateNearSurface
> mean  = g2->mean(:,ichn,:,:)
>
> Then, I get the error message:
> fatal:["Execute.c":132]:variable (mean) is not in file
> (3A-MO.GPM.DPR.V2-20170217.20151201-S000000-E235959.12.V05A.HDF5)
> fatal:["Execute.c":6316]:variable (mean) is not in file (g2)
> fatal:["Execute.c":8575]:Execute: Error occurred at or near line 95 in
> file read.ncl
>
>
> If I add the 2 lines:
> delete(mean)
> delete(g2)
>
> then I get the following error:
> fatal:file (g2) isn't defined
>
>
> Is there a way to reuse g2 for the second group? I thought that
> deleting it first would work but it does not?
>
> Thanks,
> Laura
>
>
>
> --
> !-----------------------------------------------------------
> --------------------------------------------------
> Laura D. Fowler
> Mesoscale and Microscale Meteorology Division (MMM)
> National Center for Atmospheric Research
> P.O. Box 3000, Boulder CO 80307-3000
>
> e-mail: laura at ucar.edu
> phone: 303-497-1628
>
> !-----------------------------------------------------------
> --------------------------------------------------
> _______________________________________________
> ncl-talk mailing list
> ncl-talk at ucar.edu
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20180523/d1405fd7/attachment.html>