R help - Dec 2011 - kmeans and plot labels

Hi,

Thanks Sarah. Unfortunately I did not get a step further.

My question, perhaps a bit clearer, is how to display the case control status
(or any other arbitrary point label) after clustering in a plot:

With a bit of pseudo code, where dataset is a data.frame, parameters are those
column names where we find numerical values (no NAs) and nclasses is the desired
number of classes.

fit <- kmeans(dataset[, parameters], nclasses)
plot(dataset[, parameters], col = fit$cluster, dimen = nclasses)

This gives us a nicely coloured plot where all points are circled. Yet, my
desire is to see the case / control-Status encoded in a column
"Status" with single characters, in place of those circled points.

Any hints? I did not get pch() nor text() to work. Perhaps the solution lies
there, but them I am sure that I do not see the wood for all those trees ...

TIA
Christian

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Hi,

You include no context, and I only vaguely remember your original
question. You also don't include a reproducible example.

But perhaps this helps?

testmat <- data.frame(x=c(1,1,2,3), y=c(2,1,3,2), names=letters[1:4],
stringsAsFactors=FALSE)
with(testmat, plot(x, y, pch=names))

or

with(testmat, plot(x, y, type="n"))
with(testmat, text(x, y, names))

Otherwise you'll have to actually follow the posting guide and
pose a fully self-contained question.

Sarah

On Fri, Dec 16, 2011 at 4:25 AM, Meesters, Christian <meesters at
aesku.com> wrote:
> Hi,
>
> Thanks Sarah. Unfortunately I did not get a step further.
>
> My question, perhaps a bit clearer, is how to display the case control
status (or any other arbitrary point label) after clustering in a plot:
>
> With a bit of pseudo code, where dataset is a data.frame, parameters are
those column names where we find numerical values (no NAs) and nclasses is the
desired number of classes.
>
> fit <- kmeans(dataset[, parameters], nclasses)
> plot(dataset[, parameters], col = fit$cluster, dimen = nclasses)
>
> This gives us a nicely coloured plot where all points are circled. Yet, my
desire is to see the case / control-Status encoded in a column
"Status" with single characters, in place of those circled points.
>
> Any hints? I did not get pch() nor text() to work. Perhaps the solution
lies there, but them I am sure that I do not see the wood for all those trees
...
>
> TIA
> Christian
>
-- 
Sarah Goslee
http://www.functionaldiversity.org