| 释义 |
norm A norm on a real or complex vector space V is a map ‖.‖:V →R such that (i) ‖v‖ ≥0 for all v and ‖v‖ = 0 if and only if v = 0; (ii) ‖kv‖ = |k| ‖v‖ for all v and all scalars k; (iii) ‖v + w‖ ≤ ‖v‖ + ‖w‖. Examples include the absolute value of real numbers, modulus of a complex number, p-norms, and matrix norms. The term norm is confusingly used in other contexts: see Euclidean domain, partition (of an interval).
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