[R] average by group...
I have a dataframe with 700,000 rows and 2 vectors (columns): group and score. I wish to calculate a third vector of length 70: the average score by group. Even though the avarge value will repeat, I wish to return the average for that particular group for each row. (I know I can do this by calculating each groups average and then using the merge command, but as my calculations get more complex and my data set gets larger, the merge command seems to be fairly slow.) __ 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
Re: [R] average by group...
?tapply -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of r user Sent: Tuesday, May 30, 2006 12:27 PM To: rhelp Subject: [R] average by group... I have a dataframe with 700,000 rows and 2 vectors (columns): group and score. I wish to calculate a third vector of length 70: the average score by group. Even though the avarge value will repeat, I wish to return the average for that particular group for each row. (I know I can do this by calculating each group's average and then using the merge command, but as my calculations get more complex and my data set gets larger, the merge command seems to be fairly slow.) __ 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 __ 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
Re: [R] average by group...
Doran, Harold [EMAIL PROTECTED] writes: ?tapply Nope. ?ave -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of r user Sent: Tuesday, May 30, 2006 12:27 PM To: rhelp Subject: [R] average by group... I have a dataframe with 700,000 rows and 2 vectors (columns): group and score. I wish to calculate a third vector of length 70: the average score by group. Even though the avarge value will repeat, I wish to return the average for that particular group for each row. (I know I can do this by calculating each group's average and then using the merge command, but as my calculations get more complex and my data set gets larger, the merge command seems to be fairly slow.) __ 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 __ 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 -- O__ Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 __ 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
Re: [R] average by group...
I didn't know about ave(). What about this, though: dat - data.frame(score = rnorm(100), group = gl(10,10)) group.score - with(dat, tapply(score, group, mean)) dat$group.score - group.score[as.character(dat$group)] Harold -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Peter Dalgaard Sent: Tuesday, May 30, 2006 1:09 PM To: Doran, Harold Cc: r user; rhelp Subject: Re: [R] average by group... Doran, Harold [EMAIL PROTECTED] writes: ?tapply Nope. ?ave -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of r user Sent: Tuesday, May 30, 2006 12:27 PM To: rhelp Subject: [R] average by group... I have a dataframe with 700,000 rows and 2 vectors (columns): group and score. I wish to calculate a third vector of length 70: the average score by group. Even though the avarge value will repeat, I wish to return the average for that particular group for each row. (I know I can do this by calculating each group's average and then using the merge command, but as my calculations get more complex and my data set gets larger, the merge command seems to be fairly slow.) __ 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 __ 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 -- O__ Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 __ 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
