[R] Using a function to consolidate variables

[David Young]

Dear List,

I'm getting the error: object of type 'closure' is not subsettable
And am not sure how to get around the problem.  I've included two
short code sets below.  One that shows what I want to do and works,
but without using the function much, and another that tries to use the
function but causes the error.

# THIS WORKS AND SHOWS WHAT I'D LIKE TO DO
a <- c(1,2,3)
b <- c(5,6,0)
c <- data.frame(a,b)

# TAKES THE MAX OF TWO VARS AND SAVES IT TO A NEW VARIABLE AND DELETES OLD VARIABLES
consolidate.fun <- function( data, var1, var2, saved.max ) {
max <- apply( data[,c(var1, var2)], 1, max)

# THIS WORKS BUT I HAVE TO CALL THE DATA FRAME BY NAME RATHER THEN USING THE FUNCTION DATA NAME
c[,"var.max"] <<- max  
c$a <<- NULL
c$b <<- NULL
}
consolidate.fun( data=c , var1="a", var2="b", saved.max="var.max" )
c

# THIS SHOWS THE MORE COMPLETE USE OF THE FUNCTION'S INTENT, BUT
#  CAUSES THE ERROR IN R.
a <- c(1,2,3)
b <- c(5,6,0)
c <- data.frame(a,b)

# TAKES THE MAX OF TWO VARS AND SAVES IT TO A NEW VARIABLE AND DELETES OLD VARIABLES
consolidate.fun <- function( data, var1, var2, saved.max ) {
max <- apply( data[,c(var1, var2)], 1, max)

# SOURCE OF ERROR.  I'VE TRIED CALLING THE DATA FRAME IN DIFFERENT
#  WAYS, BUT NONE SEEM TO WORK FOR ME.
data[, saved.max ] <<- max  
data[, var1 ] <<- NULL
data[, var2 ] <<- NULL
}
consolidate.fun( data=c , var1="a", var2="b", saved.max="var.max" )
c

Any helpful comments would be appreciated.


                          mailto:dyoung at telefonica.net