Hi Angelo, You can solve thins using the "melt" and "cast" functions in the "reshape" package.
Tal ----------------Contact Details:------------------------------------------------------- Contact me: tal.gal...@gmail.com | 972-52-7275845 Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) | www.r-statistics.com (English) ---------------------------------------------------------------------------------------------- On Thu, May 6, 2010 at 10:06 AM, <angelo.lina...@bancaditalia.it> wrote: > > Dear R experts, > > I am trying to solve this problem, related to the possibility of > changing the shape of a data frame using a "pivoting-like" function. > I have a dataframe df of observations as follows: > > ID VALIDITY YEAR PROPERTY PROPERTY VALUE > A1 2007 P1 V1 > A1 2007 P2 V2 > A1 2007 P3 V3 > A1 2008 P1 V10 > A1 2008 P2 V20 > A2 2007 P5 V50 > A2 2008 P6 V20 > A3 2007 P1 V1 > A3 2007 P3 V30 > A3 2008 P1 V10 > A3 2008 P2 V4 > A3 2008 P6 V25 > > (you can imagine that this data is collected every year from a sample of > people with several "measures" - weight, number of children, income... > It can happen that some properties could be missing from some IDs). > I have to obtain a data frame like this: > > > ID VALIDITY YEAR P1 P2 P3 P4 P5 P6 > A1 2007 V1 V2 V3 - - > - > A1 200 V10 V20 - - - > - > A2 2007 - - - - V50 > - > A2 2008 - - - - - > V60 > A3 2007 V1 - V30 - - > - > A3 2008 V10 V4 - - - > V25 > > > I started using the operator "by" obtaining the different "slices" of > data: > > by(df,df$PROPERTY,list) > > but then ? > > I also tried using tapply: > > tapply(df$CID,df$PROPERTY,list) > > obtaining a list but I am not able to go on. > > Can you help me ? > > Thank you in advance > > Angelo Linardi > > > > ** Le e-mail provenienti dalla Banca d'Italia sono trasmesse in buona fede > e non > comportano alcun vincolo ne' creano obblighi per la Banca stessa, salvo che > cio' non > sia espressamente previsto da un accordo scritto. > Questa e-mail e' confidenziale. Qualora l'avesse ricevuta per errore, La > preghiamo di > comunicarne via e-mail la ricezione al mittente e di distruggerne il > contenuto. La > informiamo inoltre che l'utilizzo non autorizzato del messaggio o dei suoi > allegati > potrebbe costituire reato. Grazie per la collaborazione. > -- E-mails from the Bank of Italy are sent in good faith but they are > neither binding on > the Bank nor to be understood as creating any obligation on its part except > where > provided for in a written agreement. This e-mail is confidential. If you > have received it > by mistake, please inform the sender by reply e-mail and delete it from > your system. > Please also note that the unauthorized disclosure or use of the message or > any > attachments could be an offence. Thank you for your cooperation. ** > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
