Comparative analysis of a sample relative to a database

The comparative analysis of a sample, derived from a product, with respect to a database comprises the step of determining the class membership of the different characteristics (variables) describing the samples: whether they are characteristics common to the sample under test and the database, they are characteristics particular to the sample under test, or they are characteristics particular to the database. The assignment of the variables to these classes enables parameters to be defined for global comparison of the sample under test and the database, based on: ratios summarizing the values taken by the variables of the different classes, or the distribution of the variables of the different classes. A machine implementation of the analysis is described.