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[netCDFJava #WFT-565467]: Grid API

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  • Subject: [netCDFJava #WFT-565467]: Grid API
  • Date: Fri, 25 Feb 2011 06:21:04 -0700
ok, i guess that makes sense. perhaps you should work on a branch if you have 
extensive changes? 

FYI, we will probably move to a distributed source control, like git or 
mercurial soon, because those seem to manage distributed development better.

FYI, i am going to rewrite the GRIB package sometime in the next 6 months (i 
hope). Theres a good chance i will split it from GridGrib, because theres too 
much "if (x instanceof Grib)" special stuff. I also dont like the hashtable 
approach of parameters, or at least the way Robb implemented it. If you have 
any thoughts on that, let me know.

> In the grid IOSP API (used by Grib, GEMPAK, and McIDAS) that I am trying
> to use now with GrADS, the projection and/or lat/lon coordinate
> variables are generated in GridHorizCoordSys using the parameters stored
> in GridDefRecord.  I'm trying to use this API because GrADS also
> supports GausianLatitudes and I don't want to have to reinvent all the
> code to handle that.
> 
> Don
> 
> On 2/23/11 8:20 AM, Unidata netCDF Java Support wrote:
> > I might be misunderstanding, but i think that GridHorizCoordSys is only a 
> > supporting object in the IOSP. The only thing that is seen by the higher 
> > layers is whats in a Variable. So you have to create a Variable for the 
> > lat/lons. You can generate these instead of reading them if you want.
> >
> > am i missing something?
> >
> >> John-
> >>
> >> Here's a thought on handling this.  GridDefRecord holds a hashtable of
> >> the parameters that define the grid coordinates.  Right now, the code
> >> looks for things like LA1/LO1, etc.  For an IOSP that has predefined
> >> coordinates, we could have the arrays stored in a hashtable with keys
> >> LATS and LONS.  If these are present, the values would be used in
> >> GridHorizCoordSys instead of being calculated.
> >>
> >> It would mean mods to GridDefRecord to add a table to hold objects and
> >> methods to get/set them and mods to GridHorizCoordSys to look for them
> >> and use them.  I'm thinking of using Object because different IOSPs
> >> might want to use doubles or floats and it would allow for future IOSPs
> >> to store other objects for later use.
> >>
> >> I'm willing to do the coding on this unless you have another idea.
> >>
> >> Don
> >>
> >>
> >>
> >> On 2/22/11 6:30 AM, Unidata netCDF Java Support wrote:
> >>> Hi Don:
> >>>
> >>> im not sure i understand "specify the lat/lon values ahead of time". 
> >>> Also, apparently the attachment didnt come through.
> >>>
> >>>> John-
> >>>>
> >>>> I'm making good progress on the GrADS IOSP, but have run into a hitch
> >>>> using the Grid API.
> >>>>
> >>>> In a grads file, you can specify the actual lat/lon values instead of
> >>>> just a start and increment using the LEVELS flag on XDEF or YDEF.  See
> >>>> the attached ctl file for an example.
> >>>>
> >>>> Currently there is no way in the Grid API (ucar.nc2.iosp.grid) to
> >>>> specify the lat/lon values ahead of time.  I want to use the grid API
> >>>> instead of manually making the netCDF file because of the support for
> >>>> the gaussian latitudes which GrADS supports.
> >>>>
> >>>> Thoughts on the best way to proceed?
> >>>>
> >>>> Thanks.
> >>>>
> >>>> Don
> >>>> --
> >>>> Don Murray
> >>>> NOAA/ESRL/PSD and CIRES
> >>>> 303-497-3596
> >>>> http://www.esrl.noaa.gov/psd/people/don.murray/
> >>>>
> >>>>
> >>>
> >>>
> >>> Ticket Details
> >>> ===================
> >>> Ticket ID: WFT-565467
> >>> Department: Support netCDF Java
> >>> Priority: Normal
> >>> Status: Open
> >>>
> >>
> >> --
> >> Don Murray
> >> NOAA/ESRL/PSD and CIRES
> >> 303-497-3596
> >> http://www.esrl.noaa.gov/psd/people/don.murray/
> >>
> >>
> >
> >
> > Ticket Details
> > ===================
> > Ticket ID: WFT-565467
> > Department: Support netCDF Java
> > Priority: Normal
> > Status: Open
> >
> 
> --
> Don Murray
> NOAA/ESRL/PSD and CIRES
> 303-497-3596
> http://www.esrl.noaa.gov/psd/people/don.murray/
> 
> 


Ticket Details
===================
Ticket ID: WFT-565467
Department: Support netCDF Java
Priority: Normal
Status: Open