Re: [ferret_users] 3-day running mean using boxcar filter (@sbx)

[Martin Schmidt <martin.schmidt@xxxxxxxxxxxxxxxxx>]

Samir,

if you want to fill also horizontally I suggest to have a look at 
fill_xy. It fills by averaging over all neighbours.

show func fill_xy

! as an example fill ice gaps in coads sst
use coads_climatology
! find all points that have a least one non-missing temperature value. 
If mask is 1 everywhere, everything is filled,
! if the number of steps is sufficiently large. Add "5" to avoid 
missings, where the sst is 0°C.
let mask = (sst[l=1:12@max]+5)/(sst[l=1:12@max]+5)
shade/l=10 fill_xy(sst,mask,2)

! fill more

shade/l=10 fill_xy(sst,mask,15)

This example demonstrates, how it could be used. May be a combination of 
spatial and temporal filling
would help too.

Best,
Martin


Sudheer Joseph wrote:
> Hi Samir,
>                      If you do not have gaps more than 1 day a l@fln:3 
>  if you have more lengthy gaps you may use fln:5 or so this will fill 
> the gaps by linearly interpolating between the boundaries of gaps.
>
> with best regards,
> Sudheer
>
> On Sun, Jan 13, 2013 at 8:14 PM, samir pokhrel <pokhrelsamir@xxxxxxxxx 
> <mailto:pokhrelsamir@xxxxxxxxx>> wrote:
>
>     Dear Ferret users,
>
>     I am trying to make 3-day running mean of satellite data to avoids
>     data gaps and to get complete coverage.
>
>     I have used @sbx transformation to get this, however the gap
>     increases further indicating that this transformation does not
>     account for the missing values, i.e if any grid has  missing value
>     for a time step, despite of the same grid having valid values for
>     other time step the transformation considers the final value to be
>     missing.
>
>     How to get @sbx transformation accountable for missing values
>     within a grid, similar to what @ave function  treats it, or to use
>     any other function effectively to get the running mean consisting
>     of invalid values as well.
>
>     Anticipating the replies and thanking you all in advance
>
>     Sincerely
>
>     Samir Pokhrel
>     Climate and Global Modelling Division
>     Indian Institute of Tropical Meteorology
>     NCL Post, Pashan
>     Pune-411008
>     INDIA
>
>
>
>
> --
> with best regards
>
> Sudheer
>
> **********************************************************************************
> Sudheer Joseph
> Scientist
> Indian National Centre for Ocean Information Services (INCOIS)
> Ocean Valley, Post Box No# 21,
> IDA Jeedimetla P.O.
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> Andhra Pradesh, India.
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