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Re: [ferret_users] Reduce the size of the data



Possibly this is because Ferret works by default in double precision. If you don't need double precision, you can prevent this for netcdf output with the OUTTYPE qualifier:

save/outtype=float ...

Billy

> On Mar 17, 2017, at 7:13 AM, Peter Szabo <szabpet83@xxxxxxxxx> wrote:
> 
> Dear Nicolas,
> 
> I also wonder why my file sizes always become way (usually double or 4
> times) larger than the original ones even if they share still the same
> dimensions.
> 
> The original file is 1.5 MB, while the saved out one with just values
> masked out are 6.0 MB. It is the simplest operation with a short
> formula and still making the file size way larger.
> 
> Regards,
> Peter Szabo
> 
> !FERRET v6.9
> !Linux 2.6.32-431.5.1.el6.x86_64 32-bit - 04/03/14
> 
> use TMAX7100mon_14_CCLIM.nc
> use NATER_mask.nc !THIS CONSISTS OF 1 TIME DIMENSION AND 1s WHERE THE
> MASK IS VALID
> let maszkHU=mask[d=2,gx=longitude,gy=latitude,l=1]
> let txHU=maszkHU*tx[d=1]
> save/.. txHU
> 
> 2017-03-17 11:26 GMT+01:00, Nicolas Freychet <nicolas.freychet@xxxxxxxxx>:
>> Hi all,
>> 
>> I computed the daily minimum of temperature based on 3h datasets (8
>> values/day), using the methodology (by steps of 8, I pick up the minimum
>> temperature, and associate it to the first step to record it)
>> 
>> 
>> define axis/calendar=julian/t=01-jan-1979:31-dec-1995:3/units=hours tmodel
>> repeat/range=1:49672:8/name=it (  let
>> tmin=temp[l=`it`]*0+tmin[l=`it`:`it+7`@min] ; save/append/file=Output.nc
>> Tmin[l=`it`,gt=tmodel@asn] )
>> 
>> The problem is my output file is much bigger than it should. I got the
>> impression that Ferret is recording the whole "formula" and not just the
>> value of Tmin. Is there a way to solve that?
>> 
>> (my way to define Tmin may not be optimal though, that may cause the
>> problem...)
>> 
>> Thanks,
>> Nicolas
>> 
>> 
>> 
>> ----------------------------------------------------
>> Nicolas Freychet
>> PDRA, School of Geosciences
>> University of Edinburgh
>> ----------------------------------------------------




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