Re: [R] how to call a function for each row

2011-11-30 Thread Florent D.
ofessor 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

Re: [R] how to call a function for each row

2011-11-30 Thread David L Carlson
, 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

Re: [R] how to call a function for each row

2011-11-30 Thread Bert Gunter
Homework. ? I would say that this indiicates that you need to open the R tutorials and start reading. -- Bert On Wed, Nov 30, 2011 at 5:10 AM, arunkumar 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=

Re: [R] how to call a function for each row

2011-11-30 Thread jim holtman
will this do it: > x <- read.table(text = "X1 X2 X3 + 1 3 5 + 2 4 6 + 3 6 1", header = TRUE) > x X1 X2 X3 1 1 3 5 2 2 4 6 3 3 6 1 > apply(x, 1, function(a) 6 * a[1] + 7 * a[2] + 8 * a[3]) [1] 67 88 68 > > On Wed, Nov 30, 2011 at 8:10 AM, arunkumar wrote: > Hi > >  I have

Re: [R] how to call a function for each row

2011-11-30 Thread R. Michael Weylandt
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