[R] model.frame.default problem in function definition

[Darryl Greig]

Could someone point me in the right direction for the following issue:

A function is defined as follows:

        tfun <- function(dat)
          {
            fmla <- as.formula("y~x+z")
            dat2 <- dat
            mdl <- lm(fmla,dat2)
            mdl <- step(mdl)
          }

Then the following code

        dat <- data.frame(x=1:10,z=1:10,y=(1:10)^2+10*(1:10))
        tfun(dat)

generates the output

        Start:  AIC= 43.67
         y ~ x + z

        Error in model.frame.default(formula = y ~ z, data = dat2,
drop.unused.levels = TRUE) :
                Object "dat2" not found

Any help or pointers gratefully accepted.

Thanks,
Darryl Greig ([EMAIL PROTECTED])

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