Hi Agnes,
Some functions
http://www.ncl.ucar.edu/Document/Functions/Contributed/dim_sum_Wrap.shtml
http://www.ncl.ucar.edu/Document/Functions/Built-in/dim_sum.shtml
will do that. The above could be used for (say) total precipitation
at each grid point
prcTot = dim_sum_Wrap( prc(lat|:, lon|:, time|:) )
For (say) 4x-daily [6hr totals] to get daily totals: prc(time,lat,lon)
nDay = ntim/4
prcDay = new ((/nDay,nlat,mlon/),typeof(prc),getFillValue(prc))
ndy = -1
do nt=0,ntim-1,4
ndy = ndy+1
prc(ndy,:,:) = dim_sum( prc(lat|:, lon|:, time|nt:nt+3) )
end do
-----
The following will do it for all dimensions.
http://www.ncl.ucar.edu/Document/Functions/Built-in/sum.shtml
-----
However, if you are talking about element by element sum
D = A + B + C
where A@_FillValue, A@_FillValue, C@_FillValue
then you would have to trick NCL. EG:
A@_FillValue = 0.0 ; change to zero
B@_FillValue = 0.0
C@_FillValue = 0.0
delete(A@_FillValue)
delete(B@_FillValue)
delete(C@_FillValue)
D = A + B + C
D
Agnes Lim Huei Ni wrote:
> Hi Dennis,
I may not be too clear in my previous post.
> Though there is a missing value, I still want it to sum and return
> the remaining sum instead of a missing value if one of the three
> elements is missing.
> Is that possible?
> Agnes
> Dennis Shea wrote:
NCL automatically does that. See:
http://www.ncl.ucar.edu/Document/Manuals/Ref_Manual/NclExpressions.shtml#MissingValues
Agnes Lim Huei Ni wrote:
> Hi
I have three arrays that I wish to sum. However, the elements of
> missing values are different in each of them.
> How should i code the script in order for the array to sum only
> valid values.
> Or does NCL already automatically does that.
Agnes
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Received on Mon May 04 2009 - 07:51:58 MDT
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