if you want to store the result in a column of your data.frame: within(df, Y <- 6*X1+7*X2+8*X3)
On Wed, Nov 30, 2011 at 9:59 AM, David L Carlson <dcarl...@tamu.edu> wrote: > Isn't this even easier? > >> X1 <- c(1:3) >> X2 <- c(3, 4, 6) >> X3 <- c(5, 6, 1) >> Y <- 6*X1 + 7*X2 + 8*X3 >> Y > [1] 67 88 68 > > Or if you really need a function: > >> MakeY <- function(x, y, z) 6*x + 7*y + 8*z >> MakeY(X1, X2, X3) > [1] 67 88 68 > > > ---------------------------------------------- > David L Carlson > Associate Professor of Anthropology > Texas A&M University > College Station, TX 77843-4352 > > > > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of R. Michael Weylandt > Sent: Wednesday, November 30, 2011 8:17 AM > To: arunkumar1111 > Cc: r-help@r-project.org > Subject: Re: [R] how to call a function for each row > > Read ?apply > > This is easiest: > > df <- matrix(c(1,2,3,3,4,6,5,6,1), 3) > apply(df, 1, function(x) 6*x[1]+7*x[2]+8*x[3]) > > But it's much more efficient to do it with matrix multiplication. In keeping > with the best of tradition, this is left as an exercise to the reader. > > Michael > > On Wed, Nov 30, 2011 at 8:10 AM, arunkumar1111 <akpbond...@gmail.com> wrote: >> Hi >> >> I have a data-frame which look like this >> >> X1 X2 X3 >> 1 3 5 >> 2 4 6 >> 3 6 1 >> >> I want to apply a formula Y=6*X1 + 7*X2 + 8*X3 for every row >> >> >> Thanks in Advance >> >> >> >> >> >> >> >> -- >> View this message in context: >> http://r.789695.n4.nabble.com/how-to-call-a-function-for-each-row-tp41 >> 22906p4122906.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. > > ______________________________________________ > 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.
