Re: [netcdfgroup] ncdump, then ncgen

• To: Dave Allured - NOAA Affiliate <dave.allured@xxxxxxxx>
• Subject: Re: [netcdfgroup] ncdump, then ncgen
• From: "HAVENER, KEVIN F GS-12 USAF ACC 14 WS/WXED" <kevin.havener@xxxxxxxxx>
• Date: Mon, 23 Jan 2017 20:12:38 +0000

There were obviously some things I didn't grok about ncdump.  I will revisit 
that with your suggestions.  Original file is netcdf3 and I want to write it 
back out as netcdf3, so I will do some research on the proper use of ncdump.  I 
also didn't try using plain ncgen, either.  So likely some user error involved.

Kevin Havener


-----Original Message-----
From: Dave Allured - NOAA Affiliate [mailto:dave.allured@xxxxxxxx] 
Sent: Monday, January 23, 2017 2:28 PM
To: HAVENER, KEVIN F GS-12 USAF ACC 14 WS/WXED <kevin.havener@xxxxxxxxx>
Cc: netcdfgroup@xxxxxxxxxxxxxxxx
Subject: Re: [netcdfgroup] ncdump, then ncgen

Ncdump followed by ncgen generally works fine for me.  Try using plain ncgen, 
rather than ncgen3.  Also try explicitly specifying the ncgen option to select 
netcdf-3 file format.  I recall that the default output format changed 
occasionally with different versions of ncgen, so that might be your problem.


Also remember to use -p9,17 with ncdump, if you want to preserve full precision 
from the original numeric values.  Also use the -s option with ncdump, to get 
the correct special metadata for all advanced netcdf formats (64-bit, netcdf-4, 
and netcdf4-classic).

--Dave


On Mon, Jan 23, 2017 at 6:56 AM, HAVENER, KEVIN F GS-12 USAF ACC 14 WS/WXED 
<kevin.havener@xxxxxxxxx <mailto:kevin.havener@xxxxxxxxx> > wrote:


        If I understand correctly, I should be able to ncdump a netcdf to text 
(CDL) then ncgen it back to a valid netcdf file.  I tried this on a seemingly 
valid netcdf3 file and ncgen3'd it, but the new file was not in any way like 
the old one.  In fact, it didn't even seem to be a valid netcdf3 any 
longer--the file magic was incorrect.  Did I completely misunderstand the 
capabilities of the two programs?  Or did I just not understand how to do the 
process correctly?
        
        Kevin Havener, DAFC, 14WS/WXED
        

• References:
  • [netcdfgroup] ncdump, then ncgen
    • From: HAVENER, KEVIN F GS-12 USAF ACC 14 WS/WXED
  • Re: [netcdfgroup] ncdump, then ncgen
    • From: Dave Allured - NOAA Affiliate