alignMUD is a series of mis-aligned spectra of a single small organic
molecule.
metMUD1 is composed of 20 samples, each a mixture of four typical
small organic compounds (we'll leave it to the reader as an exercise to
deduce the spin systems!). These compounds are present in varying random
amounts. Ten of the samples are control samples, and ten are treatment
samples. Thus you can run PCA and other methods on this data set, and
expect to see a separation. This data set is normalized.
metMUD2 also consists of 20 samples of mixtures of the same four
compounds. However, the concentrations of some of the compounds are
correlated with other compounds, both positively and negatively, and some
concentrations are random. metMUD2 is divided into different sample
groups which correspond conceptually to two genes, each active or knocked
out. This data set is designed to be similar to a metabolomics data set in
which the concentrations of some compounds co-vary, and others are
independent. This data set is normalized.