View the names of clustered objects

Question

I have a sample of cities of data and I am Clustering them for some parameters. But I'm having trouble representing them visually, first used the clusplot, but I can not understand why the scales change, since even plotting with only 2 components and data ranging from -1 to 1, have ranges from -4 to 4 and -2 to 2, as you can see in the example 1.

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So I use the hullplot DBSCAN package, but that plot does not show in your output the name of the cities, as clusplot, see 2. Could someone give me a suggestion of how to add these names to the chart?

Answer 1

I would try to use ggplot2 and ggrepel packages for this. I borrowed code to make the convex hull from this question.

set.seed(175)
library(ggplot2)
library(ggrepel) # Or first install.packages("ggrepel")

# Make the cluster
mtcars$cluster <- as.factor(kmeans(mtcars, 3)$cluster)

# Get the convex hull for the axes you want to plot
hull_df <- plyr::ddply(mtcars, "cluster", function(dta) {
    hull <- chull(dta$mpg, dta$disp)
    dta[c(hull, hull[1]), ]
})

ggplot(mtcars, aes(mpg, disp, color = cluster, fill = cluster)) + 
  geom_point() + 
  geom_polygon(data = hull_df, alpha = 0.5) + 
  geom_text_repel(aes(label = row.names(mtcars)))

Result: