Re: perl metar decoder -- parsing DIRmin/max wrong ?

• To: David Larson <davidl@xxxxxxxxxxxxxxxxxx>
• Subject: Re: perl metar decoder -- parsing DIRmin/max wrong ?
• From: Robb Kambic <rkambic@xxxxxxxxxxxxxxxx>
• Date: Wed, 3 Mar 2004 10:09:31 -0700 (MST)

David,

You are correct, I assumed it was the same bug  that was reported before
you. Sorry about that, your recommeded fix has been installed.

Robb...



On Wed, 3 Mar 2004, David Larson wrote:

The example bulletin I gave only had one report in it and it *did* use
the = sign to seperate reports.  It also exhibited a problem ... could
we be talking about two different problems?

I'll keep a look out for the problem to which you are referring, and
I'll have a look at your new changes.

Dave

Robb Kambic wrote:

>David,
>
>Yes, I know about the problem. The problem exists in bulletins that don't
>use the = sign to seperate reports. The solution is to assume that bulletins
>that don't use = only have one report. I scanned many raw reports and this
>seems to be true, so I changed the code to:
>
><               @reports = split ( /\n/ ) ;
>---
>
>
>>              #@reports = split ( /\n/ ) ;
>>              s#\n# #g ;
>>              next if( /\d{4,6}Z.*\d{4,6}Z/ ) ;
>>              $reports[ 0 ] = $_;
>>
>>
>
>The new code is attached.  I'm also working on a newer version of the
>decoder, it's in the ftp decoders directory. ie
>
>metar2nc.new and metar.cdl.new
>
>The pqact.conf entry needs to change \2:yy to \2:yyyy because it now uses
>the century too.  The cdl is different, merges vars that have different
>units into one.  ie wind knots, mph, and m/s are all store using winds
>m/s.  Also, store all reports per station into one record.  Take a look, I
>would appreciate any comments before it's released.
>
>Robb...
>
>
>On Tue, 2 Mar 2004, David Larson wrote:
>
>
>
>>Robb,
>>
>>I've been chasing down a problem that seems to cause perfectly good
>>reports to be discarded by the perl metar decoder.  There is a comment
>>in the 2.4.4 decoder that reads "reports appended together wrongly", the
>>code in this area takes the first line as the report to process, and
>>discards the next line.
>>
>>To walk through this, I'll refer to the following report:
>>
>>132
>>SAUS80 KWBC 021800 RRD
>>METAR
>>K4BL 021745Z 12005KT 3SM BR OVC008 01/M01 RMK SLP143 NOSPECI 60011
>>     8/2// T00061006 10011 21017 51007
>>
>>The decoder attempts to classify the report type ($rep_type on line 257
>>of metar2nc), in doing so, it classifies this report as a "SPECI" ...
>>which isn't what you'd expect by visual inspection of the report.
>>However, perl is doing the right thing given that it is asked to match
>>on #(METAR|SPECI) \d{4,6}Z?\n# which exists in the remarks of the report.
>>
>>The solution is probably to bind the text to the start of the line with
>>a caret.  Seems to work pretty well so far.
>>
>>I've changed the lines (257-263) in metar2nc-v2.4.4 from:
>>
>>    if( s#(METAR|SPECI) \d{4,6}Z?\n## ) {
>>        $rep_type = $1 ;
>>    } elsif( s#(METAR|SPECI)\s*\n## ) {
>>        $rep_type = $1 ;
>>    } else {
>>        $rep_type = "METAR" ;
>>    }
>>
>>To:
>>
>>    if( s#^(METAR|SPECI) \d{4,6}Z?\n## ) {
>>        $rep_type = $1 ;
>>    } elsif( s#^(METAR|SPECI)\s*\n## ) {
>>        $rep_type = $1 ;
>>    } else {
>>        $rep_type = "METAR" ;
>>    }
>>
>>I simply added the caret (^) to bind the pattern to the start of the report.
>>
>>Let me know what you think.
>>Dave
>>
>>
>>
>
>==============================================================================
>Robb Kambic                            Unidata Program Center
>Software Engineer III                          Univ. Corp for Atmospheric 
Research
>rkambic@xxxxxxxxxxxxxxxx               WWW: http://www.unidata.ucar.edu/
>==============================================================================
>
>
>

==============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
rkambic@xxxxxxxxxxxxxxxx                   WWW: http://www.unidata.ucar.edu/
==============================================================================