Adding variables
The station column has non numeric values, so you need convert to numeric before: with(attenu, as.numeric(as.character(station)) + mag) On Sun, Sep 27, 2009 at 8:47 AM, tzygmund mcfarlane
<tzygmund at googlemail.com> wrote:
Jim, Both my emails contained reproducible code (the first one wasn't completely reproducible - it required one to know that "attenu" is a base R dataset). Anyway, thanks for your help. On Sat, Sep 26, 2009 at 8:11 PM, jim holtman <jholtman at gmail.com> wrote:
I assumed (since you did not provide reproducible code) that 'mag' was a matrix. ?If 'station' is a matrix, then mag + rowSums(station) will work. ?If that does not work, then you need to tell us what your data objects are. On Sat, Sep 26, 2009 at 11:39 AM, tzygmund mcfarlane <tzygmund at googlemail.com> wrote:
Hi Jim, I might be missing something but your command gives the error: Error in rowSums(mag) : 'x' must be an array of at least two dimensions ############################# data(attenu) attach(attenu) rowSums(mag) + rowSums(station) attenu$new<-rowSums(cbind(mag, station)) ############################# Thanks On Sat, Sep 26, 2009 at 4:30 PM, jim holtman <jholtman at gmail.com> wrote:
Probably more efficient if you remove the 'cbind' which would create a combined matrix. ?Use the following: rowSums(mag) + rowSums(station) On Sat, Sep 26, 2009 at 11:16 AM, tzygmund mcfarlane <tzygmund at googlemail.com> wrote:
Hi, For very large matrices, is this the most efficient way to add two variables together? ############################# attach(attenu) new<-rowSums(cbind(mag, station)) ############################# Also, could I be directed to some resources for working with very large datasets? Thanks
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-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve?
-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve?
______________________________________________ R-help at 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.
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