The chart on the left is the trend and the smaller chart on the right is the box plot showing the distribution of means. Each color is the output of a particular tool. I dont need to do an ANOVA and Tukey tests on it because it can easily be seen that there are statistically significant differences between the tools. However, I would like to group/cluster the tools based on their mean.
For example, visually speaking, one can separate all the tools into 4 groups. 4 tools with a mean around
32, 12 tools with a mean around
30, 5 tools whose variance is quite high, and whose mean don't really fall into a particular group and the rest whose mean is around
I have used the k-means clustering technique and the Hierarchical Agglomeration techniques. However, I have to specify the number of clusters in advance. Is there any clustering technique where I don't have to specify the number of clusters a-priori?