In this chapter, we looked into carrying out multi-dimensional data visualization in Scala. We used JFreeChart for plotting and Breeze for optimization. Four different techniques for visualizing multi-dimensional data were considered. The first two are very simple methods that plot each of the rows in the dataset in one way or another. This presents an overview of the data.
We then looked at how you can use JFreeChart to produce a scatter plot matrix. This is a very useful tool for quickly visualizing data. It is very useful especially because it does not lose any information in the process. If the dimensionality of your dataset is fairly low, it can be used to quickly get a feel for your data.
Finally, we looked at a more involved technique called Sammon projection. It lowers the dimensionality of your data by preserving relative distances between data points. To this end, techniques from mathematical optimization are employed. We use optimization routines provided by the Breeze numerical...