Re: [datatable-help] Sum of sets of columns in data.table

Hello All, I am sure there is a much more efficient way to do this. Please advise any suggestions. For now, I have boot fixed this the crude way :-( age_brackets <- c("pop_0:pop_3","pop_4:pop_6","pop_7:pop_9") for (i in age_brackets) { cmdText <- paste('dt[, paste("",i,sep=""):= rowSums(.SD,

[datatable-help] subset data table in i with multiple criteria for multiple variables

Is there a way to subset a data table using "i" with multiple criteria using multiple variables(columns)? I have some test code shown below on what I have tried. And yes, I have read the documentation, taking the data camp class (Multiple viewing, I'm a slow learner) and have not seen anything

Re: [datatable-help] Sum of sets of columns in data.table

I come across this problem on a regular basis as well, and always end up fiddling for a while. Because the LHS of `:=` is also dynamic, I'm not sure there's any more elegant approach. One alternative might be to create several temporary data.tables holding the rowSums and then cbind()? for (i

Re: [datatable-help] subset data table in i with multiple criteria for multiple variables

 Gosh that is simple, elegant and wonderful.  Feel kinda sorta silly for not thinking of it.   Thank you for enlightening me. My Dad once said if there was a hard way to do a simple task, he was confident I would find it.  That malady has stuck with me oh so many years.  But in 10 years as an