try this:
> 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
> lapply(d, function(x) if (is.numeric(x)) c(mean=mean(x), sd=sd(x)))
$x
NULL
$y
mean sd
5.500000 3.027650
>
On Sun, Jan 11, 2009 at 9:04 PM, Jörg Groß <jo...@licht-malerei.de> wrote:
> Hi,
>
> I try to write an own function in R.
> I want a summary table with descriptive statistics.
>
>
> For example, I have this data.frame:
>
>
> d <- data.frame(c(rep("m",5), rep("f",5)), c(1:10))
> names(d) <- c("x", "y")
> d
> x y
> 1 m 1
> 2 m 2
> 3 m 3
> 4 m 4
> 5 m 5
> 6 f 6
> 7 f 7
> 8 f 8
> 9 f 9
> 10 f 10
>
>
> now I want to get the mean and sd, as long as the column is not of type
> factor.
> So the function should skip the first column.
>
>
> But how can I check this, if I don't know the column name?
>
> Because
>
> is.factor(d[1])
> produces "FALSE".
>
> Only
> is.factor(d$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?
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem that you are trying to solve?
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and provide commented, minimal, self-contained, reproducible code.
