[R] Labeling/identifying observations in plot after MclustDR from Mclust

[Jim Lemon]

On 04/17/2014 01:01 PM, Mark Manger wrote:
> Hi,
>
> I’m trying to figure out how to label points in a contour plot produced from the output of MclustDR, the dimension reduction function in the Mclust package.
>
> The original data frame has row names
>
> 		RRcoarse govtDeficit    res_gdp GrossFixedCapForm_UN fuelExports
> AUS_76    2.000  -4.5125520  1.5197260              26.5169  12.7851900
> AUS_81    3.500  -3.6041720  3.7029600              27.1058  20.8597300
> AUS_91    4.000  -1.2131010  3.8150380              24.1444  20.5832700
> AUS_01    4.000   0.0279132  4.4617860              26.9491  25.5349700
> AUT_76    2.000  -2.7850080  7.0378630              25.7365   1.6797000
> AUT_81    1.000  -3.4403770  6.4757080              23.2928   1.4688700
>
> I then use these variables to
>
> imbalances.selections.def = subset(imbalances.all, select=c(5:8,10:12), cu_gdp<  0)
> clusters.defs = Mclust(imbalances.selections.def, G=1:10)
>
>
> I use MclustDR to reduce the dimensions to plot the results, which works beautifully and produces a nice contour plot.
>
> dr.defs = MclustDR(clusters.defs)
> plot(dr.defs, what="contour”)
>
> But the plot is not particularly informative unless I know which observation is which.
>
> How can I label the points displayed in the plot to identify the observations? I can probably extract this from the dr.defs object whose str() is below, but I don’t know how to do that, or somehow from the original data frame row names. Help would be greatly appreciated. I know this is trivial in a regular plot(x,y) situation.
>
> str(dr.defs)
>
> List of 22
>   $ call         : language MclustDR(object = clusters.defs)
>   $ type         : chr "Mclust"
>   $ x            : num [1:49, 1:7] 2 3.5 4 4 2 1 1 2 2 2 ...
>    ..- attr(*, "dimnames")=List of 2
>    .. ..$ : chr [1:49] "AUS_76" "AUS_81" "AUS_91" "AUS_01" ...
>    .. ..$ : chr [1:7] "RRcoarse" "govtDeficit" "res_gdp" "GrossFixedCapForm_UN" ...
>   $ Sigma        : num [1:7, 1:7] 0.875 0.116 -0.781 -0.525 2.339 ...
>    ..- attr(*, "dimnames")=List of 2
>    .. ..$ : chr [1:7] "RRcoarse" "govtDeficit" "res_gdp" "GrossFixedCapForm_UN" …
> etc etc etc
>
Hi Mark,
I didn't see an answer to your question, but you might find the 
boxed.labels function (plotrix) helpful. I think your labels can be 
obtained using:

mylabels<-rownames(dr.defs$x)

and by calling:

boxed.labels(x,y,mylabels)

where x and y are the coordinates of the points you want to label, you 
will get the labels placed at the points. I suggest boxed.labels because 
the labels will have a little box around them and a background that 
prevents the underlying image from obscuring them.

Jim