Olga Lyashevska
2010-Aug-03 15:04 UTC
[R] multiple R sessions from one working directory using GNU screen
Dear all, I am using GNU screen to run multiple R sessions from one working directory in order to split task, however I noticed that dataset is not synchronized e.g. if I have two sessions R1 and R2, and I remove an object from R1, R2 doesn't change as expected or change at random. I have tried to save.image(), q() and then restart both sessions, but it does not help. Any suggestions? Many thanks Olga R version 2.11.1 (2010-05-31) 2010 x86_64 GNU/Linux Ubuntu 10.04.1 LTS Intel(R) Xeon(R) CPU X3220 @ 2.40GHz MemTotal: 4050180 kB
Wu Gong
2010-Aug-03 19:27 UTC
[R] multiple R sessions from one working directory using GNU screen
I don't think one session can get information from another session, except use load. I simulate you situation within one session. Hope it helps. #Simulate the first session object1 <- 1:10 save(object1,file="ob1") rm(object1) object1 #Simulate the second session object2 <- (1:10)*2 save(object2,file="ob2") rm(object2) object2 #Simulate the third session load(file="ob1") load(file="ob2") object1 object2 ----- A R learner. -- View this message in context: http://r.789695.n4.nabble.com/multiple-R-sessions-from-one-working-directory-using-GNU-screen-tp2312037p2312461.html Sent from the R help mailing list archive at Nabble.com.
Steven McKinney
2010-Aug-03 20:04 UTC
[R] multiple R sessions from one working directory using GNU screen
Dear Olga An R session is conducted entirely in the RAM memory of your computer, and each invocation of R will have its own memory space, not shared with any other application, including another R session. You will have to architect a scheme to allow one R session to find out about events and objects in another R session. This might involve writing files to disk from session R1, having session R2 check the directory for new files every now and then, and so on. (save.image() saves objects from one R session to a file on disk, but there can be other items in the saved file such as environments that are not straightforward to manipulate or investigate from another R session.) Your situation is similar to cluster computing, where a task is broken up into independent pieces and each piece is handled by a separate R process. Reading about cluster computing with R might help you figure out strategies to share bits of data and information across multiple R sessions. HTH Steven McKinney ________________________________________ From: r-help-bounces at r-project.org [r-help-bounces at r-project.org] On Behalf Of Olga Lyashevska [olga at herenstraat.nl] Sent: August 3, 2010 8:04 AM To: r-help at r-project.org Cc: Olga Lyashevska Subject: [R] multiple R sessions from one working directory using GNU screen Dear all, I am using GNU screen to run multiple R sessions from one working directory in order to split task, however I noticed that dataset is not synchronized e.g. if I have two sessions R1 and R2, and I remove an object from R1, R2 doesn't change as expected or change at random. I have tried to save.image(), q() and then restart both sessions, but it does not help. Any suggestions? Many thanks Olga R version 2.11.1 (2010-05-31) 2010 x86_64 GNU/Linux Ubuntu 10.04.1 LTS Intel(R) Xeon(R) CPU X3220 @ 2.40GHz MemTotal: 4050180 kB ______________________________________________ R-help at 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.