Extracting useful information from large data sets can be a daunting task. Topological methods for analysing data sets provide a powerful technique for extracting such information. Persistent homology ...

Data that have a multilevel structure occur frequently across a range of disciplines, including epidemiology, health services research, public health, education and sociology. We describe three ...

The problem of computing the variance of a sample of N data points {x i} may be difficult for certain data sets, particularly when N is large and the variance is ...