Following Bert Gunter's suggestion, I wonder why the data are in separate frames (with hard-coded values) in the first place. You could put them in a text file and call read.table. If you provide a header and put a meaningful station name at the start of each data row then rownames of your data frame will be meaningful.
Regards, Jorgen Harmse. From: R-help <r-help-boun...@r-project.org> on behalf of r-help-requ...@r-project.org <r-help-requ...@r-project.org> Date: Friday, 16December, 2022 at 05:00 To: r-help@r-project.org <r-help@r-project.org> Subject: [EXTERNAL] R-help Digest, Vol 238, Issue 16 Message: 1 Date: Thu, 15 Dec 2022 13:52:35 +0000 From: Stefano Sofia <stefano.so...@regione.marche.it> To: "r-help@R-project.org" <r-help@R-project.org> Subject: [R] Get data from a list of data frames Message-ID: <fe9017cbd4ba49328e15006103206...@regione.marche.it> Content-Type: text/plain; charset="utf-8" Dear R-list users, I have a list of n data frames built as follows: Station1 <- data.frame(sensor = c("thermometer", "raingauge", "snowgauge", "anemometer"), code = c(2583, 1478, 3178, NA)) Station2 <- data.frame(sensor = c("thermometer", "raingauge", "snowgauge", "anemometer"), code = c(2584, 1479, 3179, 4453)) .... Total <- list("Station1"=Station1, "Station2"=Station2, ...) I would need to have a vector with the sensor codes of the thermometers of some stations, let's say of Station1, Station2 and Station5 (i.e. c(2583, 2584, 2587)). I tried with lapply, but I have not been able to get what I need. Could you please help me? Thank you Stefano (oo) --oOO--( )--OOo-------------------------------------- Stefano Sofia PhD Civil Protection - Marche Region - Italy Meteo Section Snow Section Via del Colle Ameno 5 60126 Torrette di Ancona, Ancona (AN) Uff: +39 071 806 7743 E-mail: stefano.so...@regione.marche.it ---Oo---------oO---------------------------------------- ________________________________ AVVISO IMPORTANTE: Questo messaggio di posta elettronica pu� contenere informazioni confidenziali, pertanto � destinato solo a persone autorizzate alla ricezione. I messaggi di posta elettronica per i client di Regione Marche possono contenere informazioni confidenziali e con privilegi legali. Se non si � il destinatario specificato, non leggere, copiare, inoltrare o archiviare questo messaggio. Se si � ricevuto questo messaggio per errore, inoltrarlo al mittente ed eliminarlo completamente dal sistema del proprio computer. Ai sensi dell'art. 6 della DGR n. 1394/2008 si segnala che, in caso di necessit� ed urgenza, la risposta al presente messaggio di posta elettronica pu� essere visionata da persone estranee al destinatario. IMPORTANT NOTICE: This e-mail message is intended to be received only by persons entitled to receive the confidential information it may contain. E-mail messages to clients of Regione Marche may contain information that is confidential and legally privileged. Please do not read, copy, forward, or store this message unless you are an intended recipient of it. If you have received this message in error, please forward it to the sender and delete it completely from your computer system. -- Questo messaggio stato analizzato da Libraesva ESG ed risultato non infetto. This message was scanned by Libraesva ESG and is believed to be clean. [[alternative HTML version deleted]] ------------------------------ Message: 4 Date: Thu, 15 Dec 2022 09:31:51 -0800 From: Bert Gunter <bgunter.4...@gmail.com> To: Gerrit Eichner <gerrit.eich...@math.uni-giessen.de>, stefano.so...@regione.marche.it Cc: r-help@r-project.org Subject: Re: [R] Get data from a list of data frames Message-ID: <cagxfjbtgwq2nop0bjczct7ri6fhdmorxixv+o2-2m_-sqz6...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" Well, just for giggles, Gerrit's solution can be easily vectorized (i.e. no apply()-type stuff needed) IFF the structure of all the data frames are identical so that rbind() works: d <-do.call('rbind',Total[select.stat]) ## one data frame to combine them all ;-) d[d$sensor == 'thermometer','code'] Whether this is better, worse, or unneeded, I cannot say. Cheers, Bert [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.