[R] writing an own function - is.factor

[Jörg Groß]

Hi,

I try to write an own function in R.
I want a summary table with descriptive statistics.


For example, I have this data.frame:


  d <- data.frame(c(rep("m",5), rep("f",5)), c(1:10))
  names(d) <- c("x", "y")
  d
   	 x  y
1  	m  1
2  	m  2
3  	m  3
4  	m  4
5  	m  5
6  	f  6
7  	f  7
8  	f  8
9  	f  9
10 	f 10


now I want to get the mean and sd, as long as the column is not of  
type factor.
So the function should skip the first column.


But how can I check this, if I don't know the column name?

Because

is.factor(d[1])
produces "FALSE".

Only
is.factor(d$x)
gives the correct result.


But how can I check the column if I don't know the column name?


I tried s.th. like this;

is.factor(d$names(d[1]))


but that kind of structure is not possible.



Can someone help me with that problem?