Hi, May be this helps: dat1<-read.table(text=" Reference_Position Reference_Allele Variant_Allele Variant_Frequency AAC_Variant 16 G A 91.833811 Val6Met,Met 52 G A 93.969466 Val18Ile 64 G T 94.155381 Val22Phe 73 C A 94.293478 Gln25Lys 131 G A 94.268168 Arg44Lys 64 G A 92.947658 Ser48Asn 72 G A 85.9468 Gln25Phe 62 C A 92.6583 Arg42Lys 72 G T 96.86688 Ser48Lys ",sep="",header=TRUE,stringsAsFactors=FALSE) dat2<-dat1[,c(1,4)][duplicated(dat1$Reference_Position)|duplicated(dat1$Reference_Position,fromLast=TRUE),] dat3<-do.call(rbind,lapply(split(dat2,dat2$Reference_Position),function(x) (x[1,2]*x[2,2])/100)) dat4<-data.frame(Reference_Position=row.names(dat3),Value=dat3) row.names(dat4)<-1:nrow(dat4) merge(dat1[,c(1,4)],dat4,by="Reference_Position",all=TRUE) # Reference_Position Variant_Frequency Value #1 16 91.83381 NA #2 52 93.96947 NA #3 62 92.65830 NA #4 64 94.15538 87.51522 #5 64 92.94766 87.51522 #6 72 85.94680 83.25398 #7 72 96.86688 83.25398 #8 73 94.29348 NA #9 131 94.26817 NA
A.K. ----- Original Message ----- From: JDINIS <jorgemdi...@gmail.com> To: r-help@r-project.org Cc: Sent: Monday, October 29, 2012 12:27 PM Subject: [R] Performing multiplication on duplicate values Hello all, thank you for your help. The task I need to perform is difficult to explain so I apologize a head of time for any confusion. I have a data frame with these colnames() Reference_Position, Reference_Allele, Variant_Allele, Variant_Frequency, AAC_Variant. If a value is duplicated in the "Reference_Position" column, I would both of their "Variant_Frequency" values multiplied and inserted into a new data frame. example below: reference position 64 is repeated, multiple 94.155381 by 92.947658 and insert value into "Value". Because I do not know how to best explain this or phrase it into a logical questions, here is a before and after. Also, if you could explain the code a bit, that would be appreciated as well- teach and person to fish! Before >dat [Reference_Position] [Reference_Allele] [Variant_Allele] [Variant_Frequency] [AAC_Variant] 16 G A 91.833811 Val6Met,Met 52 G A 93.969466 Val18Ile 64 G T 94.155381 Val22Phe 73 C A 94.293478 Gln25Lys 131 G A 94.268168 Arg44Lys 64 G A 92.947658 Ser48Asn After >dat [Reference_Position] [Variant_Frequency] [Value] 16 91.833811 NA 52 93.969466 NA 64 94.155381 85.152215 73 94.293478 NA 131 94.268168 NA 64 92.947658 85.152215 -- View this message in context: http://r.789695.n4.nabble.com/Performing-multiplication-on-duplicate-values-tp4647772.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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. ______________________________________________ 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.
