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This queue is for tickets about the Geo-ReadGRIB CPAN distribution.

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The Basics
Id: 50459
Status: resolved
Priority: 0/
Queue: Geo-ReadGRIB
People
Owner: frank.l.cox [...] gmail.com
Requestors: frank.l.cox [...] gmail.com
Cc: ptomblin [...] gmail.com
AdminCc:
Bug Information
Severity: (no value)
Broken in: (no value)
Fixed in: (no value)

History Show all quoted text
  Tue Oct 13 13:44:53 2009 frank.l.cox [...] gmail.com - Ticket created
  Tue Oct 13 14:06:30 2009 frank.l.cox [...] gmail.com - Correspondence added
RT-Send-CC: ptomblin [...] gmail.com
GRIB files from http://www.weatheroffice.gc.ca/grib/High-resolution_GRIB_e.html have La1 = -90 or the south pole. Geo::ReadGRIB expects lats to run north to south and will not work correctly with these gribs without an *ugly hack*.
  Tue Oct 13 14:06:33 2009 frank.l.cox [...] gmail.com - Status changed from 'new' to 'open'
  Tue Oct 13 14:26:22 2009 frank.l.cox [...] gmail.com - Correspondence added
RT-Send-CC: ptomblin [...] gmail.com
NOAA Wavewatch III grib files have lats organized north to south and Geo::ReadGRIB was developed to work with these files. My investigation has showed that south to north is allowed and maybe even more common. I think this is a real bug.
  Tue Oct 13 14:45:22 2009 frank.l.cox [...] gmail.com - Cc ptomblin@gmail.com added
  Tue Oct 13 20:06:57 2009 frank.l.cox [...] gmail.com - Correspondence added
According to the GRIB spec, I need to look at GDS byte 17 bit 5 to see which way the lat/longs scan. Basicly, 0 = north/west to south/east, 1 = in numerical order, south/west to north/east.
  Thu Oct 15 13:00:46 2009 frank.l.cox [...] gmail.com - Correspondence added
This should be byte 28 "Scanning Mode Flag" bits 1 and 2. Byte 17 bit 5 will also be different (probably) in the two types of grib but it indicates how to resolve vector quantities. On Tue Oct 13 20:06:57 2009, FRANKCOX wrote: Show quoted text
> According to the GRIB spec, I need to look at GDS byte 17 bit 5 to see > which way the lat/longs scan. Basicly, 0 = north/west to south/east, 1 = > in numerical order, south/west to north/east. >
  Fri Oct 16 15:17:52 2009 frank.l.cox [...] gmail.com - Correspondence added
This issue has been addressed in test version Geo-ReadGRIB-0.98_2.tar.gz which has been uploaded to CPAN. It should show up in http://cpan.perl.org/authors/id/F/FR/FRANKCOX/ soon. This ticket will remain open pending testing.
  Sun Oct 18 22:03:50 2009 frank.l.cox [...] gmail.com - Correspondence added
Geo::ReadGRIB now detects the scan order of GRIB files. As of v0.98_1 it will support west/east and south/north scanning like this in addition to the west/east and north/south scanning in Wavewatch files. It will now give a message for any other not-yet-supported scanning orders asking the user to contact the module maintainer for support. I'm not expecting this but I can add support if I am made aware of such interesting GRIB files I can use for testing.
  Sun Oct 18 22:03:51 2009 frank.l.cox [...] gmail.com - Status changed from 'open' to 'resolved'