Is there a good and easy way to visualize high dimensional data?

Question

Can someone please tell me if there is a good (easy) way to visualize high dimensional data? My data is currently 21 dimensions but I would like to see how whether it is dense or sparse. Are there techniques to achieve this?

Answer 1

Parallel coordinates are a popular method for visualizing high-dimensional data.

What kind of visualization is best for your data in particular will depend on its characteristics-- how correlated are the different dimensions?