>> Provides us with a measure of the quality of any given transformed dataset. However, we still need to determine the optimal such dataset, in terms of minimising E. Strictly speaking, this is an implementation detail and the Sammon mapping itself is simply defined as the optimal transformation;

Somehow its technically challenging to verify the content of this article.

I was referencing it mostly for the visualization of the "flower" that fails with pca/linear mapping.

The original Sammon's paper is here [1], this said from what I know isomaps are a more widespread tool - but I never found such a good visualization.

[1] http://theoval.cmp.uea.ac.uk/~gcc/matlab/sammon/sammon.pdf