Re: error: constant values

The value at the pole is a constant ...
It is a singular point.

It is not an issue with the fourier function.
At the pole all longitude values are the same.

On 8/6/13 2:42 AM, Ahmad Farsyud wrote:
> Dear NCL,
>
> Thank you, actually that's not the real problem.
> even though I've changed the number of dimension as you pointed out, it
> still produced the constant values
> at the pole. So, in conclusion,I can say that by using the output of the
> Fourier filter (i.e. retain 1st of harmonics), the
> values in the pole will be CONSTANT, which I can't used on the
> calculation.(?) Then a question, why the number is constant in this case...
>
> Thank you.
>
>
>
>
> On Mon, Aug 5, 2013 at 11:22 PM, Dennis Shea <shea@ucar.edu> wrote:
>
>> You have:
>>
>> In the following "x" is 3D.
>>
>> x = f->zwn1(:,{plevx},{latS:latN},**:)
>> printVarSummary(x) ; (time,lat,lon)
>>
>> The dimension ordering in NCL is left to right (0,1,2)
>>
>> You have the followinh which is incorrect.
>> I am not sure how you decided this ordering. There are *numerous*
>> NCL examples that use dimsizes(x)
>>
>> dsizes_x = dimsizes(x)
>> nlat = dsizes_x(0) ; no
>> mlon = dsizes_x(1) ; no
>> ntim = dsizes_x(2) ; no
>>
>> It should be
>>
>> ntim = dsizes_x(0) ; time
>> nlat = dsizes_x(1) ; lat
>> mlon = dsizes_x(2) ; lon
>>
>>
>> Also, if you add the following to the end of your script
>>
>> print("====================")
>>
>> do nl=0,nlat-1
>> do ml=0,mlon-1
>> pmin = min(x(:,nl,ml))
>> pmax = max(x(:,nl,ml))
>> if(pmin.eq.pmax) then
>> print("x: all constant: nl="+nl+" ml="+ml \
>> +" "+x&lat(nl)+" "+x&lon(ml)+" val="+pmin)
>> end if
>> end do
>> end do
>>
>> You will see the the North Pole does have all constant values.
>>
>>
>>
>>
>>
>>
>>
>>
>> On 08/05/2013 02:28 PM, Ahmad Farsyud wrote:
>>
>>> Hallo NCL and Dennis,
>>>
>>> Thank you, but It seems still not solve my problem. I got the same
>>> errors (constant values).
>>> My input data is HGT anomalies with filtered harmonic 1 (fourier product).
>>> To check this closer, I have already put a mini data in ftp with name:
>>> "*z.anom.nc <http://z.anom.nc>"*
>>>
>>> and the codes to check the constant value I attached here in this email.
>>>
>>> I look forward to your help on this issue.
>>>
>>> PS: The original data I downloaded from
>>> http://www.esrl.noaa.gov/psd/**cgi-bin/db_search/DBListFiles.**
>>> pl?did=32&tid=38431&vid=663<http://www.esrl.noaa.gov/psd/cgi-bin/db_search/DBListFiles.pl?did=32&tid=38431&vid=663>
>>>
>>> and apply a spatial fiter for harmonic 1. Then check them (thus i got
>>> the constant values).
>>>
>>> I check the input data, just fine: Anomalies: Geopotential: min=-194.148
>>> max=194.148
>>> but why i still have the constant values.
>>>
>>
>>
>
>
>
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Received on Tue Aug 6 08:33:02 2013