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

[netCDFJava #RGN-330338]: Different grib2 decodings between NCL and netCDF Java library

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 Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated.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 #RGN-330338]: Different grib2 decodings between NCL and netCDF Java library
  • Date: Wed, 20 Aug 2014 13:56:26 -0600
Hi Brian:

Netcdf-Java typically sets missing values to NaNs, sounds like NCL does not.

If you can send me a sample file (and as much detail as needed to reproduce) I 
can double check if anything more nefarious is going on.

John

> Dear Sir,
> 
> I am decoding NOAA ESRL HRRR model output in grib2 format and have 
> encountered a conflict.
> 
> I am decoding the categorical precipitation fields:
> CRAIN_P0_L1_GLC0
> CFRZR_P0_L1_GLC0
> CICEP_P0_L1_GLC0
> CSNOW_P0_L1_GLC0
> 
> In particular, I am decoding CFRZR and CICEP and am getting an issue that 
> when I use NCL to view the values of these parameters, I get values of "O".
> 
> When I use netCDF-Java library 4.3.x or 4.5.2 (or NASA's Panoply tool which 
> employs netCDF-Java libraries) to view the values of these parameters, I get 
> values of "NaN".
> 
> Can you explain what is happening here? Are the values in the grib2 file 
> actually missing and being decoded in two different ways? How can I determine?
> 
> Thanks,
> Brian
> ---
> Brian Griffith, Ph.D.
> Senior Research Scientist & Site Lead
> PEMDAS Technologies & Innovations
> Phone: 828-398-8000
> address@hidden<mailto:address@hidden>
> 
> [cid:3FE592C7-C041-4CEB-8A81-855478D05A7E@hsd1.co.comcast.net.]
> CONFIDENTIALITY NOTICE: This email message and all attachments transmitted 
> with it may contain legally privileged and confidential information intended 
> solely for the use of the addressee. If the reader of this message is not the 
> intended recipient, you are hereby notified that any reading, dissemination, 
> distribution, copying, or other use of this message or its attachments is  
> strictly prohibited. If you have received this message in error, please 
> notify the sender immediately and delete this message from your system. Thank 
> you.
> 
> 
> 


Ticket Details
===================
Ticket ID: RGN-330338
Department: Support netCDF Java
Priority: Normal
Status: Open