Question

I have a more complicated function that I am working on. I want to pass a variable around inside of my function to do several things. The part that is not working is trying to access an object that has my variable’s name embedded in it.

A simple example would be as follows:

    ## Annette Dobson (1990) "An Introduction to Generalized Linear Models".
    ## Page 9: Plant Weight Data.

    ctl <- c(4.17,5.58,5.18,6.11,4.50,4.61,5.17,4.53,5.33,5.14)
    trt <- c(4.81,4.17,4.41,3.59,5.87,3.83,6.03,4.89,4.32,4.69)
    group <- gl(2,10,20, labels=c("Ctl","Trt"))
    weight <- c(ctl, trt)

    D9.fit.lm <- lm(weight ~ group)

    my.coeff <- function(mname)
       {
        b  <-  round(mname.fit.lm$coef[1],2)
        m  <-  round(mname.fit.lm$coef[2],4)
        r2 <-  round(summary(mname.fit.lm)$r.squared,2)

        cbind(b, m, r2)
       }

So if I try this bit of code like this:

 my.coeff("D9")

Then I get the following error:

 Error in my.coeff("D9") : object 'mname.fit.lm' not found

I really my function to work and it should look like this output

 cbind(round(D9.fit.lm$coef[1],2),round(D9.fit.lm$coef[2],4),round(summary(D9.fit.lm)$r.squared,2))
             [,1]   [,2] [,3]
 (Intercept) 5.03 -0.371 0.07

Thanks !

Answer 1

Just add this line inside you function

mname.fit.lm <- get(paste(mname, ".fit.lm", sep = ""))