Re: [ferret_users] seasonal means

["William S. Kessler" <william.s.kessler@xxxxxxxx>]

Hi Izidine -

I misread your earlier message (did not notice that each month was in  
a separate file). Sorry. But now I see that you have all years in a  
single file.

Then use the method in my last message (set dat climatological_axes).  
The axis seasonal_reg will make a proper seasonal climatology  
correctly and straightforwardly:

set dat climatological_axes
let cru_seasonal = cru[gt=seasonal_reg@mod]

This will give you traditional seasonal averages of JFM, AMJ, JAS, OND.

If you want DJF,MAM,JJA,SON, then use axis month_reg or month_irreg  
and average the months you want:

let cru_monthlycl = cru[gt=month_reg@mod] 	! 12-month climatology
let cru_3monthav = cru_monthlycl[l=@sbx:3] 		! running 3-month average
save/file=cru_seasonal_alt.nc cru_3monthav[l=1:10:3]  		! save only  
DJF,MAM,JJA,SON

==>> Then check by listing a few locations of your previous result as  
below, and comparing with the DJF value in the method above!!!

Billy K

On 16 Sep 09, at 10:34 AM, Izidine Pinto wrote:

> Dear ferreters
>
> I have a .nc file (CRU data), which contains monthly climatological  
> values (15-jan-1901,15-feb-1901,16-mar-1901......16-dec-2002) .
> I would like to make seasonal climatology (DJF,MAM,JJA,SON)  from  
> 1981 to 1999 and save the result in a single file.
> For DJF I did in this way
>
> set data crutmx.nc
> let djf1=cru[l=972:974@ave]
> let djf2=cru[l=984:986@ave]
> let djf3=cru[l=996:998@ave]
> let djf4=cru[l=1008:1010@ave]
> let djf5=cru[l=1020:1022@ave]
> let djf6=cru[l=1032:1034@ave]
> let djf7=cru[l=1044:1046@ave]
> let djf8=cru[l=1056:1058@ave]
> let djf9=cru[l=1068:1070@ave]
> let djf10=cru[l=1080:1082@ave]
> let djf11=cru[l=1092:1094@ave]
> let djf12=cru[l=1104:1106@ave]
> let djf13=cru[l=1116:1118@ave]
> let djf14=cru[l=1128:1130@ave]
> let djf15=cru[l=1140:1142@ave]
> let djf16=cru[l=1152:1154@ave]
> let djf17=cru[l=1164:1166@ave]
> let djf18=cru[l=1176:1178@ave]
>
> let mean=(djf1+djf2+djf3+djf4+djf5+djf6+djf7+djf8+djf9+djf10+djf11 
> +djf12+djf13+djf14+djf15+djf16+djf17+djf18)/18
> save /file=djfcru.nc mean
>
> I have to do for others season.
> There are another way of doing this?
>
> Thanks in advance
>
> --
> Izidine Pinto
> 33.55 S 18.22 E