> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Jim Lemon > Sent: Tuesday, July 15, 2008 5:03 PM > To: Rheannon > Cc: r-help@r-project.org > Subject: Re: [R] Row Sum, exclude positive values > > On Tue, 2008-07-15 at 14:35 -0700, Rheannon wrote: > > Hello, > > > > I'd like to sum the values of a row from the first negative > number (FN) to > > the last negative number (LN), but not add any positive > values to the sum. > > Then apply this to each row of the data frame. > > > > For example if I have a dataframe with Row 1 values > > DF = (4, 3, 2, 1, 0, -1, -2, -3, -2, 2, 1, -1, -2, -3, -2, -1, 1, 2) > > I would like to sum the numbers from column 6 to column 16, > but not include > > column 10 & 11. > > > Hi Rheannon, > > How about: > > sum(DF[DF<0]) > > Jim
If you actually have a data frame and want to do this row by row, you could do something like >sumneg <- function(x) sum(x[x<0]) >apply(DF,1,sumneg) Hope this is helpful, Dan Daniel J. Nordlund Washington State Department of Social and Health Services Planning, Performance, and Accountability Research and Data Analysis Division Olympia, WA 98504-5204 ______________________________________________ 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.
