macro facility in R

Try this:

# test data
set.seed(1)
mat <- matrix(rnorm(900), nc = 9)
colnames(mat) <- letters[1:9]
DF <- as.data.frame(mat)

# run lm's and display coefs
for(i in seq(1, 5, 2)) {
dat <- cbind(z = DF[,i] - DF[,i+1], DF[7:9])
Coef <- coef(lm(z ~., dat))
cat("y: DF[,", i, "] - DF[,", i+1, "], coef: ", Coef, "\n")
}

On 7/3/06, John Sorkin <jsorkin at grecc.umaryland.edu> wrote:

R 2.2 on windows XP
I have a dataset with multiple columns. Some of the columns 
represent
independent variables, some represent dependent variables. I would 
like
to run the same analyses on a fixed set of independent variables,
changing only the dependent variable, e.g.
y1-y2=x1+x2+x3
y3-y4=x1+x2+x3
y5-y6=x1+x2+x3, etc.
I know I can write a function to perform the analyses, however in 
order
to make the analyses easy to do, I really need a macro scripting
language that will allow preprocessing of the function and 
substitution
of macro variables with parameters passed to the macro, i.e. I need
someting akin to the macro facility in SAS. Is there a macro 
facility
that I can use with R? I have tried help.search("macro") and did 
not
have any success.
Thanks,
John

John Sorkin M.D., Ph.D.
Chief, Biostatistics and Informatics
Baltimore VA Medical Center GRECC,
University of Maryland School of Medicine Claude D. Pepper OAIC,
University of Maryland Clinical Nutrition Research Unit, and
Baltimore VA Center Stroke of Excellence

University of Maryland School of Medicine
Division of Gerontology
Baltimore VA Medical Center
10 North Greene Street
GRECC (BT/18/GR)
Baltimore, MD 21201-1524

410-605-7119
jsorkin at grecc.umaryland.edu