R: Recipes for Analysis, Visualization and Machine Learning

Validating clusters externally

Besides generating statistics to validate the quality of the generated clusters, you can use known data clusters as the ground truth to compare different clustering methods. In this recipe, we will demonstrate how clustering methods differ with regard to data with known clusters.

Getting ready

In this recipe, we will continue to use handwriting digits as clustering inputs; you can find the figure on the author's Github page: https://github.com/ywchiu/ml_R_cookbook/tree/master/CH9.

How to do it...

Perform the following steps to cluster digits with different clustering techniques:

1. First, you need to install and load the package png:

   > install.packages("png")
   > library(png)
   

2. Then, please read images from handwriting.png