Re: calculating total emissions

From: Dennis Shea <shea_at_nyahnyahspammersnyahnyah>
Date: Tue Dec 15 2009 - 16:17:53 MST

Something like:
   http://www.ncl.ucar.edu/Document/Functions/Built-in/wgt_areasum2.shtml

---
Also
   gridPointTot = dim_sum_n_Wrap( aFCH4 , 0)
   gridTot = gridPointTot*WGTS
where WGTS is the area of each drid point.
---
In *all* interpreted languages multiple level doo loops
with multiple steps should be avoided if possible.
Unlike (say) fortran, there is no compiler to perform
code optimization. For example,
 >                     diff_lon = 2.8152d*3.14159265d/180.0d
 >                     R=6371.0d*1000.0d ; unit is meterncd
WHy repeat this every step?
Lei Meng wrote:
> Hi,
>    I was wondering if there are some faster ways to calculate globally 
> total emissions. I used the following code and it looped over each grid 
> cell to calculate total values. It takes so long to finish the calculation.
> --------------------------
> totalfch4=0.0d
>    do i =0, natime-1
>         do j=0,nalat-1
>          rlat2= (alat(j)+1.429)*3.14159265/180.0 ; convert degree to radians
>          rlat1= (alat(j)-1.429)*3.14159265/180.0
>          temp1 = sin(rlat2)
>          temp2 = sin(rlat1)
>          temp = temp1-temp2  
>      
>             do k=0,nalon-1
>                  if(.not.ismissing(aFCH4(i,j,k))) 
> then                       
>                     diff_lon = 2.8152d*3.14159265d/180.0d
>                     R=6371.0d*1000.0d ; unit is meterncd
>                     area=R*R*diff_lon*temp
>                     if(area.lt.0) then
>                        area=0.0
>                     end if
>                     totalfch4=aFCH4(i,j,k)*area             ; convert 
> from kgC/m2/s to kgC/s by multiplying area
>                     afch4(i) = afch4(i)+totalfch4
>                   end if
>             end do
>        end do
>   end do
> ------------------------------------
> Any suggestions would be appreciated. Thanks,
> Lei
> 
> 
> ------------------------------------------------------------------------
> 
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Received on Tue Dec 15 16:19:00 2009

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