[gradsusr] Fw: EOF and spectral analysis on GrADS

[Lee Byerle]

Opengrads has some of these capabilities, see this link for more details:

http://opengrads.org/doc/udxt/shfilt/shfilt.html

Lee


Sent from my iPhone

On Jan 27, 2013, at 11:51 AM, tcavazos at cicese.mx wrote:

> Hi,
> 
> Yes, there is a script in Grads to obtain EOFs (PCA), I think it is from
> Brian Coty (?), but I do not have the information here. I installed it in
> one of my computers like ten 10 ago... But I am not aware of spectral
> analysis on Grads.
> 
> Tereza
> 
>> Dear Tamer Nada
>> 
>> Thank you by your explanation and suggestions. They were clear.
>> 
>> By the way do you know where can I found the fortran subroutines from
>> lepak library you commented?
>> 
>> 
>> Thanks in advance
>> 
>> Enviado via iPad
>> 
>> Em 26/01/2013, às 16:53, Tamer Nada <tamer540 at gmail.com> escreveu:
>> 
>>> Dear :- Jose Augusto Paixão Veiga
>>> 
>>> In Fortran :-
>>> 
>>> You must know there is about 3 methods ( algorithms )  to calculate
>>> eigen Vector and eigen Value  each method some of it efficient but just
>>> compute only first Eigen value and first Eigen vector by suggest value
>>> and using iteration methods to compute it until reach to the difference
>>> between old value from last iteration to new value equal small fraction
>>> you can determine it . another to methods using "SVD "  and this method
>>> its divided by to relative to the shap of data matrix   and some of it
>>> efficient but slow and some fast and not efficient
>>> 
>>> I suggest to you to use lepak library in fortran ( its easy to call
>>> subroutine ) or using high level language or statistical or climatic
>>> package like NCL or R or Matlab
>>> 
>>> On Sat, Jan 26, 2013 at 9:56 PM, Jose Augusto Paixão Veiga
>>> <veiga.uea at gmail.com> wrote:
>>>> Dear EOF expertise,
>>>> 
>>>> one of you would have a material given instruction (if possible step by
>>>> step) on how to calculate EOF?
>>>> 
>>>> I would like to do a fortran program, from the initial point (for
>>>> example: 1-read a 3-d matrix data, 2-calculate its inversion,
>>>> 3-multiply it by its ....), to calculate EOF for climate study
>>>> purposes.
>>>> 
>>>> A flux diagram will be very appreciated.
>>>> 
>>>> Thanks in advance.
>>>> 
>>>> Augusto
>>>> 
>>>> 
>>>> On Jan 26, 2013, at 3:41 PM, Tamer Nada <tamer540 at gmail.com> wrote:
>>>> 
>>>>> on Grads No, but you can use NCL  or R to compute EOF; and Only R  or
>>>>> Matlab to Compute CCA ,But also you can Use NCL to compute "SVD" and
>>>>> after that you can compute CCA ,actually NCL have function to compute
>>>>> CCA ,But not efficient because  its use old IBM Fortran subroutine ,so
>>>>> its not work fine with big array of data and may be hang in
>>>>> calculation ,so i prefer to use SVD function and after that you can
>>>>> compute CCA
>>>>> 
>>>>> On Sat, Jan 26, 2013 at 9:58 AM, ugo okoro <uknac23 at yahoo.com> wrote:
>>>>>> 
>>>>>> Dear all,
>>>>>> 
>>>>>> Please any info on how to run EOF and spectral analysis
>>>>>> (frequency-time) on GrADS?
>>>>>> 
>>>>>> Anticipating prompt response.
>>>>>> 
>>>>>> Thanks.
>>>>>> 
>>>>>> Ugo Okoro.
>>>>>> CMSR-IAP
>>>>>> CAS, Beijing.
>>>>>> 
>>>>>> _______________________________________________
>>>>>> gradsusr mailing list
>>>>>> gradsusr at gradsusr.org
>>>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>> 
>>>>> 
>>>>> 
>>>>> --
>>>>> =====================
>>>>> Tamer Ali Nada
>>>>> Research Worker
>>>>> Cairo Numerical Weather Prediction Center { CNWP}
>>>>> Egyption Meteorological Authority   { EMA }
>>>>> Cairo , Egypt
>>>>> ============================
>>>>> tamer540 at yahoo.com
>>>>> tamer540 at gmail.com
>>>>> tamer.nada at noaa.gov
>>>>> _______________________________________________
>>>>> gradsusr mailing list
>>>>> gradsusr at gradsusr.org
>>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>> 
>>>> 
>>>> _______________________________________________
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>>> 
>>> 
>>> 
>>> --
>>> =====================
>>> Tamer Ali Nada
>>> Research Worker
>>> Cairo Numerical Weather Prediction Center { CNWP}
>>> Egyption Meteorological Authority   { EMA }
>>> Cairo , Egypt
>>> ============================
>>> tamer540 at yahoo.com
>>> tamer540 at gmail.com
>>> tamer.nada at noaa.gov
>>> _______________________________________________
>>> gradsusr mailing list
>>> gradsusr at gradsusr.org
>>> http://gradsusr.org/mailman/listinfo/gradsusr
>> _______________________________________________
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> 
> 
> -- 
> Tereza Cavazos
> Departamento de Oceanografia Fisica
> CICESE
> Ensenada, Baja California, MEXICO
> http://usuario.cicese.mx/~tcavazos/
> 
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