Hi,

I have a question about the usage of eval(). Wonder if any experienced user can help me out of it.

I use eval() in the following function:
semireg.pwl <- function(coef.s=rnorm(1),coef.a=rnorm(1),knots.pos=knots.x,knots.ini.val=knots.val){
knotn <- length(knots.pos)
def.par.env <- sys.frame(1)
print(def.par.env)
print(environment(coef.s))
tg <- eval( (parse(text=
             paste(
                 "function(coef.sex=coef.s,coef.age=coef.a,",
                 paste("knot.val.",1:knotn,"=knots.ini.val[",1:knotn,"]",sep="",collapse=","),
                 ")",
                 "{\n print(sys.frame());print(coef.sex)\n y <- c(",
                 paste("knot.val.",1:knotn,sep="",collapse=","),
                 ")\n",
                 " -loglikelihood(coef.sex,coef.age,knots.pos,y)\n}",
                 sep="",collapse=""
                 )
             )
         )
        ,envir=def.par.env)
print(tg())
print(coef.s)
print(sys.frame(1))
mle(tg)
}

But when I ran semireg.pwl(), I got correct value for tg(), but an message
"Error in eval(expr, envir, enclos) : Object "coef.s" not found"
for mle(tg). I just don't know how to make the environment variable visible for mle().

Thanks a lot!

Feng
 [[alternative HTML version deleted]]

______________________________________________
R-help@(protected)
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html