On Wed, 2005-06-22 at 17:12 +0200, [EMAIL PROTECTED] wrote: > I receive the following meteo dataset regularly, containing the average > daily temperatures (tMedia) of a certain month for 24 selected meteo-stations > (COD_WMO) whose human-readable names are in (NOME). > > str(tabella) > `data.frame': 1038 obs. of 4 variables: > $ COD_WMO: int 16045 16045 16045 16045 16045 16045 16045 16045 16045 16045 > ... > $ NOME : Factor w/ 24 levels "ALGHERO","BARI/PALESE MACCHIE",..: 22 22 > 22 22 22 22 22 22 22 22 ... > $ DATE :'POSIXct', format: chr "2005-05-01" "2005-05-02" "2005-05-03" > "2005-05-04" ... > $ tMedia : num 11.7 18.6 16.9 19.7 15.0 ... > > > Here you are a short list of it: > COD_WMO NOME DATE tMedia > 505 16191 FALCONARA 2005-06-01 20.95 > 506 16191 FALCONARA 2005-06-02 20.15 > 507 16191 FALCONARA 2005-06-03 18.60 > 506 16191 FALCONARA 2005-06-02 20.15 > 507 16191 FALCONARA 2005-06-03 18.60 > 508 16191 FALCONARA 2005-06-04 22.30 > 509 16191 FALCONARA 2005-06-05 NA > 510 16191 FALCONARA 2005-06-06 NA > 511 16191 FALCONARA 2005-06-07 18.20 > 549 16206 GROSSETO 2005-06-01 20.65 > 550 16206 GROSSETO 2005-06-02 21.95 > 551 16206 GROSSETO 2005-06-03 22.25 > 552 16206 GROSSETO 2005-06-04 20.15 > 553 16206 GROSSETO 2005-06-05 NA > 554 16206 GROSSETO 2005-06-06 NA > 555 16206 GROSSETO 2005-06-07 22.35 > ..................................................................... > ..................................................................... > > > I need to rearrange tMedia into a new dataframe whose column names are COD_WMO > (or NOME) and the row is DATE. > > ex. > DATE ALGHERO BARI/PALESE .... FALCONARA GROSSETO .......... > 2005-06-01 16.3 12.8 17.3 > 14.0 ........... > 2005-06-02 18.2 8.9 18.0 > 17.9 .......... > ............................................................................................... > > > I read some pieces of R-docs in the internet and run the MASS chapter 2 > examples but without finding anything suitable to my purpose. > > Could you please help me? > > Ciao > > Vittorio
I believe that the following will get you there, based upon your example output above: > reshape(tabella[, -1], idvar = "DATE", timevar = "NOME", v.names = "tMedia", direction = "wide") DATE tMedia.FALCONARA tMedia.GROSSETO 1 2005-06-01 20.95 20.65 2 2005-06-02 20.15 21.95 3 2005-06-03 18.60 22.25 6 2005-06-04 22.30 20.15 7 2005-06-05 NA NA 8 2005-06-06 NA NA 9 2005-06-07 18.20 22.35 See ?reshape for more information. HTH, Marc Schwartz ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html