To sum it up straight away: First and foremost I am looking for software to create something like this (advanced cluster diagram?) from a data set.
A (very small) sample data set looks like this:
+-----------+-----------+-----------+-----------+-----------+
| | Cluster 1 | Cluster 2 | Cluster 3 | Cluster 4 |
+-----------+-----------+-----------+-----------+-----------+
| Cluster 1 | - | 4 | 4 | 1 |
| Cluster 2 | 2 | - | 2 | 3 |
| Cluster 3 | 3 | 0 | - | 2 |
| Cluster 4 | 1 | 2 | 0 | - |
+-----------+-----------+-----------+-----------+-----------+
Depending on the number the cluster would be closer together or further away. The more cluster are close to one cluster, the more inflated it gets.
So on a higher level: I need a software (web app, desktop app, JavaScript library, whatever) to create these types of diagrams from input data I specify.