What is procrustes distance?

Procrustes distance is a statistical measure that is used to compare the similarity in shape and size of two different datasets. More specifically, it is a term from the field of multivariate statistics and is applicable to datasets with more than one variable or attribute. The distance measure is calculated by aligning and scaling the two datasets such that the means and variances are equal, and then computing the sum of squared differences between the corresponding points in the two datasets. It is used in a variety of applications, including image analysis, morphometric studies, and pattern recognition, to name just a few. Procrustes distance has the advantage of being scale-invariant, meaning that it is not influenced by differences in size or magnitude between the two datasets being compared.