Hello, I have sample data set that looks like: YEAR MONTH DAY CONTINUE SPL TIMEFISH TIMEUNIT AREA COUNTY DEPTH DEPUNIT GEAR TRIPID CONVUNIT 1992 1 26 1 SP0073928 8 H 7 25 4 NA 1000000 02163399054 161 1992 1 26 1 SP0073928 8 H 7 25 4 NA 1000000 02163399054 8 1992 1 26 2 SP0004228 8 H 7 25 4 NA 1000000 02163399054 161 1992 1 26 2 SP0004228 8 H 7 25 4 NA 1000000 02163399054 8 1992 1 25 NA SP0052652 8 H 7 25 4 NA 1000000 02163399057 85 1992 1 26 NA SP0037940 8 H 7 25 4 NA 1000000 02163399058 70 1992 1 27 NA SP0072357 8 H 7 25 4 NA 1000000 02163399059 15 1992 1 27 NA SP0072357 8 H 7 25 4 NA 1000000 02163399059 20 1992 1 27 NA SP0026324 8 H 7 25 4 NA 1000000 02163399060 8 1992 1 28 1 SP0072357 8 H 7 25 4 NA 1000000 02163399062 200
How can I use unique to extract the rows that have repeated tripid's only, not a unique value for each variable but only for TRIPID. I then want to condense the unique values by summing the CONVUNIT for each unique value of TRIPID. I posted a similar question last week and received a sufficient answer of how to do this without using uniqe. The solution below worked just fine on this sample data set but the full data set has 446,000 rows of data and my computer and R simply cannot handle this follwing code on data this large. conds<-by(Step4,Step4$TRIPID,function(x) replace(x[1,],"CONVUNIT",sum(x$CONVUNIT))) Step5<-do.call(rbind,conds) Thank you, Cameron Guenther, Ph.D. Associate Research Scientist FWC/FWRI, Marine Fisheries Research 100 8th Avenue S.E. St. Petersburg, FL 33701 (727)896-8626 Ext. 4305 [EMAIL PROTECTED] ______________________________________________ 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
