Dear R-list users,

let me ask you a very general question about performance of big data frames.

I deal with semi-hourly meteorological data of about 70 sensors during 28 
winter seasons.


It means that for each sensor I have 48 data for each day, 181 days for each 
winter season (182 in case of leap year): 48 * 181 * 28 = 234,576

234,576 * 70 = 16420320


>From the computational point of view it is better to deal with a single data 
>frame of approximately 16.5 M rows and 3 columns (one for data, one for sensor 
>code and one for value), with a single data frame of approximately 235,000 
>rows and 141 rows or 70 different data frames of approximately 235,000 rows 
>and 3 rows? Or it doesn't make any difference?

I personally would prefer the first choice, because it would be easier for me 
to deal with a single data frame and few columns.


Thank you for your usual help

Stefano


         (oo)
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Stefano Sofia MSc, PhD
Civil Protection Department - Marche Region - Italy
Meteo Section
Snow Section
Via Colle Ameno 5
60126 Torrette di Ancona, Ancona (AN)
Uff: +39 071 806 7743
E-mail: stefano.so...@regione.marche.it
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