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Re: 20050922:DODS/THREDDS confusion



Hi David:

The problem is that the opendap server ("DAP++ 3.5.2") uses this form for 
Strings:

forecasttime:   Array of Strings [record = 0..4][time_len = 0..20]
   * long_name: "forecast date and time"

using the "translate a char into a String" method.

However, the THREDDS server uses variable length Strings:

forecasttime:   Array of Strings [record = 0..4]
   * long_name: "forecast date and time"
   * DODS:
         o strlen: 21
         o dimName: time_len

using the "strlen Convention" to tell the client what the String lengths are.


Does anyone on dods-tech know if the opendap-netcdf client library will support 
the latter?
He has version "netCDF Client Library 3.5.2"

Unidata Support wrote:
------- Forwarded Message


To: address@hidden
From: David Wojtowicz <address@hidden>
Subject: DODS/THREDDS confusion
Organization: UCAR/Unidata
Keywords: 200509221824.j8MIOEYJ003573


Hi,


I'm primarily using the Dataset Viewer to browse the catalog and locate DODS URL's that I access in my own applications via the latest OpenDAP libraries.
2) If I locate an entry inside "Previous version OPeNDAP NetCDF  
Server" I can get a DODS URL like this:
    http://motherlode.ucar.edu/cgi-bin/dods/DODS-3.4.3/nph-dods/dods/ 
model/2005092215_ruc_211.nc
I can do a  "dncdump -h" on that URL and get the expected header  
info.... and also use this URL within my own programs to access the  
dataset.
However, I'm reluctant to continue using that as the name "Previous  
version" implies that it's being replaced by something newer and is  
going to go away.
The "new" entries such as under "NCEP Model Data (netCDF) "  I get  
different OpeNDAP URLs that look like:
   http://motherlode.ucar.edu:8080/thredds/dodsC/model_nc/ 
ruc_211/2005092213_ruc_211.nc
If I pass this URL  to "dncdump -h"  I get output that is both  
incomplete and contains invalid data.   Tried this with a number of  
other data files in the same area.
The "NCDUMP" function in the Dataset Viewer program however, seems to  
work fine.
Is this a different format/protocol?    I'm using the latest  
available SDKs...  "DAP++ 3.5.2" and "netCDF Client Library 3.5.2"   
that I downloaded from opendap.org and compiled myself under linux.
I'm further frustrated by the fact that most of the documentation/ 
status pages that I find on www.unidata.ucar.edu haven't been updated  
in a while and don't reflect recent changes.

David Wojtowicz, Sr. Research Programmer
Dept of Atmospheric Sciences / Computer Services
University of Illinois at Urbana-Champaign
address@hidden  (217) 333-8390



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