|

»

»

How to combine two rows (in a dataframe) into a third row?

View: New views

4 Messages — Rating Filter: Alert me

	How to combine two rows (in a dataframe) into a third row? by Mark Na :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message Dear R-helpers, I have two rows in my dataframe: ID VALUE 1A 10 1B 15 and I would like to combine these two rows into a single (new) row in my dataframe: ID VALUE 1 25 ...simply by specifying a new value for ID and summing the two VALUES. I have been trying to do this with with rbind, but it's not working. I'd appreciate any pointers. Thanks, Mark Na [[alternative HTML version deleted]] ______________________________________________ R-help@... 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.
	Re: How to combine two rows (in a dataframe) into a third row? by Peter Alspach :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message Tena koe Mark ?tapply with the index argument some suitable substring of your ID column. HTH .... Peter Alspach > -----Original Message----- > From: r-help-bounces@... > [mailto:r-help-bounces@...] On Behalf Of Mark Na > Sent: Friday, 10 July 2009 10:28 a.m. > To: r-help@... > Subject: [R] How to combine two rows (in a dataframe) into a > third row? > > Dear R-helpers, > > I have two rows in my dataframe: > > ID VALUE > 1A 10 > 1B 15 > > and I would like to combine these two rows into a single > (new) row in my > dataframe: > > ID VALUE > 1 25 > > ...simply by specifying a new value for ID and summing the two VALUES. > > I have been trying to do this with with rbind, but it's not working. > > I'd appreciate any pointers. > > Thanks, Mark Na > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@... 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. > The contents of this e-mail are confidential and may be subject to legal privilege. If you are not the intended recipient you must not use, disseminate, distribute or reproduce all or any part of this e-mail or attachments. If you have received this e-mail in error, please notify the sender and delete all material pertaining to this e-mail. Any opinion or views expressed in this e-mail are those of the individual sender and may not represent those of The New Zealand Institute for Plant and Food Research Limited. ______________________________________________ R-help@... 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.
	Re: How to combine two rows (in a dataframe) into a third row? by Henrique Dallazuanna :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message Try this: aggregate(x["VALUE"], list(substr(x[,"ID"], 1, 1)), sum) On Thu, Jul 9, 2009 at 7:27 PM, Mark Na <mtb954@...> wrote: > Dear R-helpers, > > I have two rows in my dataframe: > > ID VALUE > 1A 10 > 1B 15 > > and I would like to combine these two rows into a single (new) row in my > dataframe: > > ID VALUE > 1 25 > > ...simply by specifying a new value for ID and summing the two VALUES. > > I have been trying to do this with with rbind, but it's not working. > > I'd appreciate any pointers. > > Thanks, Mark Na > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@... 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[alternative HTML version deleted]] ______________________________________________ R-help@... 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.
	Re: How to combine two rows (in a dataframe) into a third row? by Mark Na :: Rate this Message: Reply to Author \| View Threaded \| Show Only this Message Hi Henrique & other R-helpers, Thank you for helping me last week. I used Henrique's suggestion to develop some code (below) to combine two rows in my dataframe into a third row, and then delete the original two rows. It works well. My solution is not very elegant however; if there's a function (or a better way) to accomplish this in 1-2 lines (rather than my 6) I'd appreciate knowing about it. Many thanks, Mark Na #make some data for this example data<-data.frame(c("1A","1B"),c("10","15")) names(data)<-c("id","value") data$value<-as.numeric(as.character(data$value)) #combine two lines into one by summing their values in the value column fixed<-data.frame() #create empty data frame to hold fixed rows fixed<-rbind(fixed, aggregate(data["value"],list(substr(data[,"id"],1,1)), sum)) #copy previous line as necessary for other fixes names(fixed)<-c("id","value") #fix column names #bind the fixed line to the main dataframe and delete the original lines data<-rbind(data,fixed) #add fixed lines to data data<-data[-which(c("1A","1B") %in% data$id),] #delete lines from data rownames(data) <- 1:nrow(data) #renumber rows On Thu, Jul 9, 2009 at 5:58 PM, Henrique Dallazuanna <wwwhsd@...>wrote: > Try this: > > aggregate(x["VALUE"], list(substr(x[,"ID"], 1, 1)), sum) > > On Thu, Jul 9, 2009 at 7:27 PM, Mark Na <mtb954@...> wrote: > >> Dear R-helpers, >> >> I have two rows in my dataframe: >> >> ID VALUE >> 1A 10 >> 1B 15 >> >> and I would like to combine these two rows into a single (new) row in my >> dataframe: >> >> ID VALUE >> 1 25 >> >> ...simply by specifying a new value for ID and summing the two VALUES. >> >> I have been trying to do this with with rbind, but it's not working. >> >> I'd appreciate any pointers. >> >> Thanks, Mark Na >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@... 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. >> > > > > -- > Henrique Dallazuanna > Curitiba-Paraná-Brasil > 25° 25' 40" S 49° 16' 22" O > [[alternative HTML version deleted]] ______________________________________________ R-help@... 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.