Try
> x <- read.table(textConnection(
+ "1.2 1
+ 1.2 1
+ 1.3 1
+ 1.5 1
+ 1.1 2
+ 1.2 2
+ 9.9 2
+ 0.1 3
+ 1.1 3
+ 1.9 3") )
> x.min <- tapply(x[,1], x[,2], min)
> x[x.min[x[,2]]==x[,1],]
V1 V2
[1,] 1.2 1
[2,] 1.2 1
[3,] 1.1 2
[4,] 0.1 3
2009/10/29 Ista Zahn
> I still don't under
I still don't understand. Please look at the example I provided in my
last response. What is it that you want that my example does not do?
On Thu, Oct 29, 2009 at 3:08 PM, Waverley @ Palo Alto
wrote:
> The reason %in% does not work is that there are might be values which
> are not min in other cl
The reason %in% does not work is that there are might be values which
are not min in other class which are the same as the min of different
classes. In the example I provided before, this situation did not
exist. See the new example:
> + 1.2 1
> + 1.3 1
> + 1.5 1
> + 1.1 2
> + 1.2 2
> + 9.9 2
>
Hi,
I guess I don't understand why you think %in% won't work.
> x <- read.table(textConnection("1.2 1
+ 1.2 1
+ 1.3 1
+ 1.5 1
+ 2.1 2
+ 2.0 2
+ 9.9 2
+ 1.4 3
+ 1.8 3
+ 1.9 3") )
> x <- as.matrix(x)
> x.min <- tapply(x[,1], x[,2], min)
> x[x[,1] %in% x.min,]
> ## all matches
V1 V2
[1,] 1.2 1
Thanks. That works.
However, in my own case, there are more columns of other kinds of
data. So to me, it is more important to get the row index of those
that has the min values of particular column in particular class
(which is another column).
Can you help more as how to get those row index? O
tapply(x, y, min)
where x is the vector of numbers and y the vector of class labels.
Best,
--
Wolfgang Viechtbauerhttp://www.wvbauer.com/
Department of Methodology and StatisticsTel: +31 (0)43 388-2277
School for Public Health and Primary Care Office Location:
Maast
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