[Met_help] Persistance Calculations in MET

[John Halley Gotway]

Jeff,

That's interesting that you wrote about persistence today.  I've actually been talking to Robert Craig at AFWA over the last couple of days about persistence in regards to how you guys compute the Go
Index.

But the answer to your question is no, MODE does not currently do any computations with regards to persistence.  The closest thing to this in MET right now is in Point-Stat - you can pass it a gridded
field containing "climatological" values.  Then it'll dump out additional line types, SAL1L2 and VAL1L2, for scalar and vector anomaly partial sums.  But we don't have any pre-defined scheme for doing
anything with persistence.

That being said, we'd be happy to work with you guys to discuss ways to enhance the MET tools to better meet your needs.  The MET statistics tools, Point-Stat, Grid-Stat, MODE, and Wavelet-Stat,
operate on a single field at a single point in time.  However, the analysis tools, Stat-Analysis and MODE-Analysis, aggregate and summarize results through time and/or space.  It may be possible to
add functionality to these analysis tools to better handle the persistence calculations you'd like to see.

Thanks,
John

Hamilton, Jeffrey A CIV USAF AFWA 16 WS/WXN wrote:
> John,
> 
> Have a quick question for you in regards to MET. An issue that keeps
> coming up from our modelers is the presence of persistence in the MODE
> calculations. We are wondering if persistence is even calculated in MET
> and, if so, what is the scheme by which it is?
> 
> Thanks and hope you had a great New Year!
> 
> 
> // SIGNED //
> JEFF HAMILTON, Civ SCEP
> Model Analysis Team
> 16 WS/ WXN
> Air Force Weather Agency
> Offutt AFB, NE 68113
> (402) 232-7207
> 
> 
> 
> -----Original Message-----
> From: John Halley Gotway [mailto:johnhg at ucar.edu] 
> Sent: Friday, November 13, 2009 1:23 PM
> To: Hamilton, Jeffrey A CIV USAF AFWA 2 WXG/; met_help
> Subject: Re: masking options
> 
> Jeff,
> 
> There is, in fact, a flag in the MODE config file that does exactly what
> you're looking for.  Try turning on the "plot_valid_flag" in the config
> file, as shown below:
> 
> //
> // If the plot_valid_flag is set, only the region containing valid data
> // after the masking is applied will be plotted:
> // (0) Plot the entire domain of the data
> // (1) Plot only the region containing valid data after masking
> //
> plot_valid_flag = 1;
> 
> Just let us know if any more questions come up.
> 
> Thanks,
> John
> 
> Hamilton, Jeffrey A CIV USAF AFWA 2 WXG/ wrote:
>> John,
>>
>>  
>>
>> I had a quick question about the masking tool in MET MODE. I have been
>> able to mask an area of the globe using the polygon option, however,
> the
>> graphic that appears still shows the worldwide view, making it
> difficult
>> to distinguish the objects in the masked area. I am wondering if there
>> was any way to additionally mask the graphic showing the objects,
> along
>> with the data itself, in order to visually analyze the objects?
>>
>>  
>>
>> Thanks for any input you might have,
>>
>>  
>>
>> // SIGNED //
>>
>> JEFF HAMILTON, Civ SCEP
>>
>> Model Verification
>>
>> 2 WXG/ WEA
>>
>> Air Force Weather Agency
>>
>> Offutt AFB, NE 68113
>>
>> (402) 232-7207
>>
>>  
>>
>>