Distance (
\(d_{i,j}\)) between two objects (
\(i\) and
\(j\)) calculated as the sum of the absolute difference between
\(k\) variables (
\(x\)) that describe the objects.
\[d_{i,j} = \sum\limits_{k\,=\,1}^{k\,=\,N} \vert x_{i,k} - x_{j,k}\vert\]Source:
PAC, 2016, 88, 407. 'Vocabulary of concepts and terms in chemometrics (IUPAC Recommendations 2016)' on page 427 (https://doi.org/10.1515/pac-2015-0605)