question about the resulting dendrograms in hierarchical clustering

I have a question about the resulting dendrogram in hierarchical clustering.

I have 64 items that need to clustered by hierarchical clustering. Following the documentation in Matlab, I computed the pdist (because each item is a vector of size 6); then I computed for the linkage.

And the resulting dendrogram is shown here:

Question:

1. I am supposed to have 64 items, where are the rest? I am only seeing a few of them? I tried zooming out but I didn't see them.

Answer 1

[OCDER]

Dendrogram defaults to 30 leaf nodes to draw. To draw more, specify # of leaf nodes to draw.

Y = linkage(rand(64, 3));
dendrogram(Y, size(Y,1)+1)

https://www.mathworks.com/help/stats/dendrogram.html