CODEWITHSUNDEEP
rrstudio
Pixelements
Pixelements

Reputation: 15

Rstudio - my dendogram as black bars?

So basically, I've created a big dendogram in RStudio and I've already tried many things out. I've tried to plot the names vertically, I've tried to give my dataframe-columns simple names like 1,2,3,..,11 and so on. But I can't figure out, why I'm getting these odd black bars?! I Can't see the names of my Variables.. Do you have any clue?

Dendogram black bars:
Dendogram black bars

Upvotes: 0

Views: 363

Answers (1)

giac
giac

Reputation: 4309

At the bottom of your dendogram, you have all the identifiers you used in your clustering. When you have a lot of identifiers, then you can't see them all because they are "stacked" next to each others. This is what produced the "black bars". 

library(cluster)
d = daisy(mtcars)
hc = hclust(as.dist(d), method = "ward")

There is little you can do about this. However, you can try to manipulate the cex argument. 

plot(hc, cex = 0.5)

Here I reduced the size of the identifier.

enter image description here

One solution in order to retrieve the identifiers is to do this.

Let us imagine that we choose a solution of 3 clusters. 

clusters = cutree(hc, k = 3)

Then you can do 

dt = as.data.frame(clusters) 
dt$carsID = row.names(dt)

library(dplyr)
dt %>% arrange(clusters)

   clusters              carsID
1         1           Mazda RX4
2         1       Mazda RX4 Wag
3         1          Datsun 710
4         1           Merc 240D
5         1            Merc 230
6         1            Merc 280
7         1           Merc 280C
8         1            Fiat 128
9         1         Honda Civic
10        1      Toyota Corolla
11        1       Toyota Corona
12        1           Fiat X1-9
13        1       Porsche 914-2
14        1        Lotus Europa
15        1        Ferrari Dino
16        1          Volvo 142E
17        2      Hornet 4 Drive
18        2             Valiant
19        2          Merc 450SE
20        2          Merc 450SL
21        2         Merc 450SLC
22        2    Dodge Challenger
23        2         AMC Javelin
24        3   Hornet Sportabout
25        3          Duster 360
26        3  Cadillac Fleetwood
27        3 Lincoln Continental
28        3   Chrysler Imperial
29        3          Camaro Z28
30        3    Pontiac Firebird
31        3      Ford Pantera L
32        3       Maserati Bora

Then you can see all the identifiers.

Upvotes: 1

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