On physical units in multivariate analysis
comparatively stringent mathematical frame has been developed, where the behaviour of physical dimensions (like ``length'', ``mass'', and ``time'') and physical units (like 1 m [1 metre], 1 kg [1 kilogramme], and 1 s [1 second]) is modelled. Easy-to-apply conditions for additivity and multiplicativity of physcial matrices are presented. Precise meanings of physically dimensional random variables,
