Re: average & std. deviation for non-contiguous time slices

If you have complete year, then, as suggested by Gus,
the clmMon* functions will do.

Otherwise

     clmavg = new (/12,nlat,mlon/), typeof(x), getFillValue(x))
     clmstd = clmavg

     do nmo=0,11
        clmavg(nmo,:,:) = dim_avg_n(x(nmo::12,:,:), 0)
        clmstd(nmo,:,:) = dim_stddev_n(x(nmo::12,:,:), 0)
     end do

On 3/12/14, 11:03 AM, Gus Correa wrote:
> On 03/12/2014 11:02 AM, Ray Sambrotto wrote:
>>
>> I am trying to implement a statistical comparison similar to the one in
>> the climo1.ncl example script. The problem is that I am working with
>> satellite imagery that is irregularly spaced in time and not monthly
>> climatology so I don’t think I can use clmMonLLT & stdMonLLT. Also, the
>> dim_sum_n function requires all of the data to be in the same file,
>> which these are not. I suppose I could construct such a file from the
>> separate data files.
>>
>> My question is: Is there a better method for finding the average and
>> standard deviation of a non-contiguous group of time slices?
>>
>> Thanks, Ray Sambrotto
>>
>> -----------
>> Lamont-Doherty Earth Observatory
>> 61 Rt. 9W / Palisades, NY 10964 USA
>>
> Hi Ray
>
> I am not familiar to satellite data format,
> but I guess you could use a variable on a regular grid with
> missing values on the data gaps.
>
> clmMonLLT uses dim_avg, and stdMonLLT uses dim_stddev,
> both of which claim to ignore missing values in their calculations.
>
> Say, using "new", you could create a data(lat,lon,time)
> variable with a _FillValue of your choice (or perhaps better,
> the same _FillValue that is used on your files).
> "data" should be large enough to hold all actual data
> (i.e. have maximum spatial and time coverage).
> You probably need to create "named" dimensions for it too.
>
> Then fill in the "data" variable using the various files,
> but honoring the (spatial and) time gaps the data may have.
> This may depend on how the data is organized on the files
> (one or more time records per file, full or partial spatial coverage
> per file, etc).
>
> Finally apply the clmMonLLT and stdMonLLT to
> the "data" variable.
>
> I hope this helps,
> Gus Correa
>
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Received on Wed Mar 12 12:53:34 2014