Measurement results on a system arranged in a
\(m \times n\) matrix, with
\(m\) objects and
\(n\) variables.
Notes: - By convention a matrix is arranged with \(m\) rows and \(n\) columns.
- Objects are also called "samples", but confusion with physical "test samples" in analytical chemistry should be avoided.
- Variables are also called features, or explanatory variables.
- For multi-way data the data is arranged in a hypercube of \(m \times n_{1} \times n_{2} \times\) …, where \(n_{1}\), \(n_{2}\) … are the kinds of explanatory variable.
Source:
PAC, 2016, 88, 407. 'Vocabulary of concepts and terms in chemometrics (IUPAC Recommendations 2016)' on page 409 (https://doi.org/10.1515/pac-2015-0605)