Multivariate Data Analysis
Computer Practical 3
This computer practical can be accessed via the course web page:
It may be helpful to have the course web page, the course notes, and
this practical page all open in different tabs of your web browser
during this practical session. In particular, it may save time to
copy-and-paste R commands rather than re-typing them.
- Work through all of the R code in the notes from p.58 to
p.75. Make sure you understand it all before proceeding.
- Working with the zip.train data set, create a subset of
the data corresponding to the digit "5". How many "5"s are
there in the data set?
- Working with the subset defined above, compute the Mahalanobis
distances of the "5" digits (from the sample mean). Find the
images with the largest and smallest Mahalanobis distances,
and produces images of these two. Are they as you expected?
Hint: you may find the commands which.max() and
- You may also use this practical session to ask about any last-minute questions
you may have regarding Project 1.