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[netCDFPerl #GTU-862479]: Problems with NetCDF::varget

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  • Subject: [netCDFPerl #GTU-862479]: Problems with NetCDF::varget
  • Date: Tue, 03 Sep 2013 15:37:27 -0600
Alex,

> I have to read a NetCDF file in which a variable (LONGITUDE) is defined, with 
> attributes, but in the values part of the file there is no data for this 
> variable (the variable doesn't exist in fact)
> 
> The code I user is :
> 
> $l_varId = NetCDF::varid($p_file, $p_variable);
> $l_status = NetCDF::varinq($p_file, $l_varId, \$l_name, \$l_datatype, 
> \$l_dimCount, \@l_dimIds, \$l_atts);
> if ($l_status == -1)
> {
> Print "$p_variable doesn't exist\n";
> }
> else
> {
> $l_status = $TRUE;
> $l_dimSizes[$l_dimCount - 1] = undef;
> NetCDF::diminq($p_file, $l_dimIds[0], \$l_name, \$l_dimSizes[0]);
> NetCDF::varget($p_file, $l_varId, [0], [$l_dimSizes[0]], \@l_fileValues);
> }
> 
> And I get the following message : "ncvarget: ncid 10; varid 20: Index exceeds 
> dimension bound" and the script stops immediately.
> 
> I tried the same with an "eval block" like ths :
> 
> $l_varId = NetCDF::varid($p_file, $p_variable);
> $l_status = NetCDF::varinq($p_file, $l_varId, \$l_name, \$l_datatype, 
> \$l_dimCount, \@l_dimIds, \$l_atts);
> if ($l_status == -1)
> {
> Print "Error reading $p_variable\n";
> }
> else
> {
> $l_status = $TRUE;
> $l_dimSizes[$l_dimCount - 1] = undef;
> NetCDF::diminq($p_file, $l_dimIds[0], \$l_name, \$l_dimSizes[0]);
> eval
> {
> NetCDF::varget($p_file, $l_varId, [0], [$l_dimSizes[0]], \@l_fileValues);
> };
> if($@)
> {
> CoScrReport::SendError("Variable $p_variable has no values : $@");
> }
> }
> 
> But I still have the same error message and the script stops.
> 
> Questions : how can I catch the error to write an user friendly  error 
> message and that the script doesn't stops immediately ?

You have to use the NetCDF::opts(i) function to tell the netCDF library not to 
exit if an error occurs. Valid values are 0, NetCDF::FATAL (1), NetCDF::VERBOSE 
(2), or a bitwise OR of these values. I would call NetCDF::opts(0).

> Thanks for your response.
> 
> Best regards
> 
> Alex THEPAUT

Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: GTU-862479
Department: Support netCDF Perl
Priority: Normal
Status: Closed