[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[netCDFJava #IPI-729759]: subset across the grid boundary

This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.

  • Subject: [netCDFJava #IPI-729759]: subset across the grid boundary
  • Date: Fri, 19 Nov 2010 10:38:16 -0700
Hi HansPeter,

The issue has come up before and is on our list. However, it isn't currently 
close enough to the top of the list to have a timeline.

How are you using this data when you want to make a cross-seam subsetting 
request? Are you using netCDF-java directly or accessing it in the IDV or some 
other application that uses netCDF-java? Do you want to be able to make these 
requests against data files on your local disk as well as remote data?

The netCDF-java library deals mainly with array index space rather than 
lat/lon, this includes the gridded data API. The simplest solution might be to 
provide some utility methods that client applications could use to construct 
the appropriate queries and stitch together the results. There might be some 
extensions to the API that would simplify things for the client application but 
we would need to be careful not to change the current API in ways that would 
affect existing code.

If you have any thoughts on what approach seems reasonable from your end, let 
us know.

Thanks,

Ethan

HansPeter Roesli wrote:
> Hi -
> 
> Every now and then, with a grib file at hand that spans 0° to 360°
> longitude (or 180° to '180°?), I stumble over the problem of not being
> able to subset it across the grid boundary at 0° (180°?). Of course,
> this problem can be overcome by subsetting the data set prior to the
> creation of the grib file, but this is not always convenient.
> 
> It appears that this problem has to be solved at NetCDF-java level. I do
> not think to be the only user to request this, so I am sure it is
> somewhere on the to-do list. May I please ask you for a timeline when
> that could be done.
> 
> Thank you very much for considering this issue, HP
> Hi -
> 
> Every now and then, with a grib file at hand that spans 0° to 360°
> longitude (or 180° to '180°?), I stumble over the problem of not being
> able to subset it across the grid boundary at 0° (180°?). Of course,
> this problem can be overcome by subsetting the data set prior to the
> creation of the grib file, but this is not always convenient.
> 
> It appears that this problem has to be solved at NetCDF-java level. I do
> not think to be the only user to request this, so I am sure it is
> somewhere on the to-do list. May I please ask you for a timeline when
> that could be done.
> 
> Thank you very much for considering this issue, HP

Ticket Details
===================
Ticket ID: IPI-729759
Department: Support netCDF Java
Priority: Normal
Status: Closed