I have been using multidimensional scaling thanks to the R implementation of igraph. The command I have employed is `igraph::layout_with_mds()`

that works pretty fast. My questions are:

- What is the functional that the algorithm minimizes? According to sources like this, there are several forms of functionals that can be minimized.
- What is the numerical algorithm that is used for the minimization?

Thanks in advance for any insight.