if else statements in R

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This is untested, so try it first, but my approach would be:

W<- function(w)
{
W[i]<-ifelse(comp[i,1]==1, Wo, (work[i-1,5]work[i-1,13]*/Ef))
}

Best,
Andy Perrin

----------------------------------------------------------------------
Andrew J Perrin - http://www.unc.edu/~aperrin
Assistant Professor of Sociology, U of North Carolina, Chapel Hill
clists at perrin.socsci.unc.edu * andrew_perrin (at) unc.edu

Hi, there

I am a grad student struggling to get my syntax right in a model I am
building in R.

I am trying to specify a variable,W, in a loop, such that on the first
iteration, it is equal to Wo, my starting value, which I have already
specified with

Wo<-9.2

  On any other iteration other than the first, I want W to equal the
previous value of W in the iteration. plus an increment from that previous
iteration, divided by another value.  This then becomes the value used in
all calculations in the iteration at hand.

Here is my code, that does not work:

W<- function(w)
{
if (comp[i,1]=1) W[i]<-Wo else
W[i]<-(work[i-1,5]work[i-1,13]*/Ef)
}

"work" is the dataframe that I am rbinding my interations into, and the W
variable is the 5th variable in that frame, and the additive to W is the
13th variable in that frame.

However, this is where the program stalls on me:

{
+
+ W<- function(w)
+ {
+ if (comp[i,1]=1) W[i]<-Wo else
Error: syntax error
Execution halted

I've also attempted this variation;

W<- function(w)

if (comp[i,1]=1) {W[i]<-Wo} else
W[i]<-(work[i-1,5]work[i-1,13]*/Ef)

Which meets with an equal lack of success, and stalls in the same spot as
the previous version.

Does anyone have any hints on how to make this if else statement work to do
what I need?  This is my first time trying to use these statements, and the
S-plus manual i have is proving to be terribly unhelpful.

What am I doing wrong?

Mike

Michael Rennie
M.Sc. Candidate
University of Toronto at Mississauga
3359 Mississauga Rd. N.
Mississauga, ON  L5L 1C6
Ph: 905-828-5452  Fax: 905-828-3792
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W<- function(w)
{
if (comp[i,1]=1) W[i]<-Wo else
"==" is comparison operator, but "=" is assignment one.
This code also doesn't work:
x <- 0
if (x = 1)
Error: syntax error

But this works:
if (x == 1)
+ 

Chack also help("=="), help("=")

--
WBR,
Timur.