How to specify linewidth in Seaborn's clustermap dendrograms

Question

Normally I would increase matplotlib\'s global linewidths by editing the matplotlib.rcParams. This seems to work well directly with SciPy\'s dendrogram implementation but not wi

Answer 1

This has now been addressed in a more robust way by the following merged pull request https://github.com/mwaskom/seaborn/pull/1935. I'm assuming it will be included in the release after v0.9.0.

You can control the LineCollection properties of the dendrogram by using the tree_kws parameter.

For example:

>>> import seaborn as sns
>>> iris = sns.load_dataset("iris")
>>> species = iris.pop("species")
>>> g = sns.clustermap(iris, tree_kws=dict(linewidths=1.5, colors=(0.2, 0.2, 0.4))

Would create a clustermap with 1.5 pt thick lines for the tree in an alternative dark purple color.