[Met_help] some questions about point_stat

[John Halley Gotway]

Ruifang,

Thanks for sending those files.  Let me start by making a suggestion that you turn OFF the matched pair output line (MPR) from Point-Stat.  Do this by changing the value for it in the "output_flag"
parameter.  You're generating files that are unnecessarily large.  The MPR line type is only meant to be used in debugging or testing mode.  You probably shouldn't use it for large runs!

I did look at the MPR line type in this case.  I looked at the matched pairs for TMP, Z02, ADPSFC, UW_MEAN, and 1.  For the FULL domain, I see 2742 pairs and for the T8 domain, I see 2744 pairs.
Those numbers are very close but they're counter intuitive.  It seems like they should be switched.  You should have more matched pairs in the FULL domain than in the T8 domain.  I looked at the
lat/lon's of the observation points for the 2 that are in T8 but not in full.  They both have longitude = -104.8, which I'm guessing is right on the boundary of your domain.

I have no idea why those 2 are included in T8 but not in FULL.  I went hunting through the code to see if I could figure out why, but I didn't turn anything up.  I think it might be a rounding issue
along the boundary when converting back and forth between lat/lon and x/y.

Thanks,
John

Ruifang Li wrote:
> Hi, John,
> I tested only 2007081512 for you to look at this time.
> 
> You can look at all my data on
> /ptmp/lir/test/data/2009_t8_15km/verify_met2.0/gsi/point_stat
> 
> Thanks for help,
> Ruifang
> 
> 
> On Thu, Jul 30, 2009 at 10:58 AM, Ruifang Li <lir at ucar.edu> wrote:
> 
>> Hi, John,
>> I am a little bit confused about mask_grid and mask_poly in point_stat
>> config file.
>>
>> In pb2nc, I defined mask_grid=" ", mask_poly="MET_BASE/data/poly/T8.poly",
>> so I got obs for T8 domain since my WRF fcst are on this domain.
>> In point_stat, I did several test about mask_grid and mask_poly , here is
>> the result
>>
>>                                     * mask_grid[]    mask_poly[]   domain
>> in .stat     .stat file size*
>>
>>                                          FULL               T8
>>       FULL,T8             7,017,368
>>                                                                  T8
>>            T8                       3,010,624
>> --                                       FULL
>>         FULL                  3,507,520
>>
>>  My question are:
>>
>>    -  it's better to define both of mask_poly and mask_grid or only one of
>>    them is enough?
>>    - If I define both of mask_poly and mask_grid, the FULL and T8 records
>>    show up in .stat file, is there any difference between FULL and T8 records?
>>
>>
>> Thanks for your help,
>> Ruifang
>>
>> Mesoscale & Microscale Meteorology Division
>> Phone: 303-497-8938
>> Office:  FL3-3085
>> Email:  lir at ucar.edu
>>
> 
> 
> 
> 
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