Е. Деза_ М.М. Деза. Энциклопедический словарь расстояний (2008) (1185330), страница 57
Текст из файла (страница 57)
äÓ‰˚, ̇ ÍÓÚÓ˚ı ‰ÓÒÚË„‡ÂÚÒfl ‡‚ÂÌÒÚ‚Ó, ̇Á˚‚‡˛ÚÒfl ‡Á‰ÂÎËÚÂθÌ˚ÏË ÍÓ‰‡ÏË Ò Ï‡ÍÒËχθÌ˚Ï ‡ÒÒÚÓflÌËÂÏ.ç‡Ë·ÓΠ˜‡ÒÚÓ ËÒÔÓθÁÛÂÏ˚Ï ‡ÒÒÚÓflÌËÂÏ ÏÂÊ‰Û ÍÓ‰Ó‚˚ÏË ÒÎÓ‚‡ÏË Ï‡Ú˘ÌÓ„Ó ÍÓ‰‡ C ⊂ Mm, n ( Fq ) fl‚ÎflÂÚÒfl ı˝ÏÏË̄ӂ‡ ÏÂÚË͇ ̇ M m,n(Fq ), ÓÔ‰ÂÎÂÌ̇flÍ‡Í || A − B || H , „‰Â || A || H – ‚ÂÒ ï˝ÏÏËÌ„‡ χÚˈ˚ A ∈ Mm,n(Fq ), Ú.Â.
˜ËÒÎÓ ÌÂÌÛ΂˚ı ˝ÎÂÏÂÌÚÓ‚ χÚˈ˚ Ä.252ó‡ÒÚ¸ IV. ê‡ÒÒÚÓflÌËfl ‚ ÔËÍ·‰ÌÓÈ Ï‡ÚÂχÚËÍÂê‡ÒÒÚÓflÌË ‚Á‡ËÏÓÓ·ÏÂ̇ê‡ÒÒÚÓflÌË ‚Á‡ËÏÓÓ·ÏÂ̇ (ËÎË ‡ÒÒÚÓflÌË ҂ÓÔ‡) ÂÒÚ¸ ÏÂÚË͇ ̇ ÍӉ ë ⊂ ṅ‰ ‡ÎÙ‡‚ËÚÓÏ , ÓÔ‰ÂÎÂÌ̇fl ‰Îfl β·˚ı x, y ∈ C Í‡Í ÏËÌËχθÌÓ ˜ËÒÎÓ Ò‚ÓÔÓ‚(Ú‡ÌÒÔÓÁˈËÈ), Ú.Â. ÔÂÂÒÚ‡ÌÓ‚ÓÍ ÒÏÂÊÌ˚ı Ô‡ ÒËÏ‚ÓÎÓ‚, ÌÂÓ·ıÓ‰ËÏÓ ‰Îfl ÔÂÓ·‡ÁÓ‚‡ÌËfl ı ‚ Û.ê‡ÒÒÚÓflÌË ÄëåÖê‡ÒÒÚÓflÌË ÄëåÖ – ˝ÚÓ ÏÂÚË͇ ̇ ÍӉ ë ⊂ n ̇‰ ‡ÎÙ‡‚ËÚÓÏ , ÓÔ‰ÂÎÂÌ̇fl ͇Ímin{d H ( x, y), d I ( x, y)},„‰Â dH – ı˝ÏÏË̄ӂ‡ ÏÂÚË͇, ‡ dI – ‡ÒÒÚÓflÌË ÔÂÂÒÚ‡ÌÓ‚ÓÍ.ê‡ÒÒÚÓflÌË ‚ÒÚ‡‚ÍË-Û‰‡ÎÂÌËèÛÒÚ¸ W – ÏÌÓÊÂÒÚ‚ÓÏ ‚ÒÂı ÒÎÓ‚ ̇‰ ‡ÎÙ‡‚ËÚÓÏ . 쉇ÎÂÌË ·ÛÍ‚˚ ‚ ÒÎÓ‚Âβ = b1 ...bn ‰ÎËÌ˚ n ÂÒÚ¸ ÔÂÓ·‡ÁÓ‚‡ÌËÂ β ‚ ÒÎÓ‚Ó β ′ = b1 ...bi −1bi +1 ...bn ‰ÎËÌ˚ n – 1.ÇÒÚ‡‚͇ ·ÛÍ‚˚ ‚ ÒÎÓ‚Ó β = b1 ...bn ‰ÎËÌ˚ n ÂÒÚ¸ ÔÂÓ·‡ÁÓ‚‡ÌËÂ β ‚ ÒÎÓ‚Óβ ′′ = b1 ...bi bbi +1 ...bn ‰ÎËÌ˚ n + 1.ê‡ÒÒÚÓflÌË ‚ÒÚ‡‚ÍË-Û‰‡ÎÂÌËfl (ËÎË ‡ÒÒÚÓflÌË ÍÓ‰Ó‚ Ò ËÒÔ‡‚ÎÂÌËÂÏ Û‰‡ÎÂÌËÈ Ë‚ÒÚ‡‚ÓÍ) ÂÒÚ¸ ÏÂÚË͇ ̇ W, ÓÔ‰ÂÎÂÌ̇fl ‰Îfl β·˚ı α, β ∈ W Í‡Í ÏËÌËχθÌÓ˜ËÒÎÓ Û‰‡ÎÂÌËÈ Ë ‚ÒÚ‡‚ÓÍ ·ÛÍ‚, ÔÂÓ·‡ÁÛ˛˘Ëı α ‚ β.äÓ‰ ë Ò ËÒÔ‡‚ÎÂÌËÂÏ Û‰‡ÎÂÌËÈ Ë ‚ÒÚ‡‚ÓÍ – ÔÓËÁ‚ÓθÌÓ ÍÓ̘ÌÓ ÔÓ‰ÏÌÓÊÂÒÚ‚Ó ÏÌÓÊÂÒÚ‚‡ W.
èËÏÂÓÏ Ú‡ÍÓ„Ó ÍÓ‰‡ fl‚ÎflÂÚÒfl ÏÌÓÊÂÒÚ‚Ó ÒÎÓ‚nβ = b1 ...bn ‰ÎËÌ˚ n ̇‰ ‡ÎÙ‡‚ËÚÓÏ = {0, 1}, ‰Îfl ÍÓÚÓÓ„Ó∑ ibi ≡ 0(mod n + 1).i =1∑1äÓ΢ÂÒÚ‚Ó ÒÎÓ‚ ‚ ˝ÚÓÏ ÍӉ ‡‚ÌÓφ( k )2 ( n +1) / k , „‰Â ÒÛÏχ ·ÂÂÚÒfl ÔÓ2(n + 1) k‚ÒÂÏ Ì˜ÂÚÌ˚Ï ‰ÂÎËÚÂÎflÏ k ˜ËÒ· n + 1, ‡ φ – ÙÛÌ͈Ëfl ùÈ·.àÌÚ‚‡Î¸ÌÓ ‡ÒÒÚÓflÌËÂàÌÚ‚‡Î¸ÌÓ ‡ÒÒÚÓflÌË (ÒÏ., ̇ÔËÏÂ, [Bata95]) – ÏÂÚË͇ ̇ ÍÓ̘ÌÓÈ „ÛÔÔ (G, +, 0), ÓÔ‰ÂÎÂÌ̇fl ͇Íw int(x – y),„‰Â wint(x) – ËÌÚ‚‡Î¸Ì˚È ‚ÂÒ Ì‡ G, Ú.Â. ÌÓχ „ÛÔÔ˚, Á̇˜ÂÌËfl ÍÓÚÓÓÈ fl‚Îfl˛ÚÒflÔÓÒΉӂ‡ÚÂθÌ˚ÏË ÌÂÓÚˈ‡ÚÂθÌ˚ÏË ˆÂÎ˚ÏË ˜ËÒ·ÏË 0,..., m.
ùÚÓ ‡ÒÒÚÓflÌËÂËÒÔÓθÁÛÂÚÒfl ‚ „ÛÔÔÓ‚˚ı ÍÓ‰‡ı C ⊂ G.åÂÚË͇ î‡ÌÓåÂÚËÍÓÈ î‡ÌÓ Ì‡Á˚‚‡ÂÚÒfl ÏÂÚË͇ ‰ÂÍÓ‰ËÓ‚‡ÌËfl, Ô‰̇Á̇˜ÂÌ̇fl ‰ÎflÓÔ‰ÂÎÂÌËfl ̇ËÎÛ˜¯ÂÈ ‚ÓÁÏÓÊÌÓÈ ÔÓÒΉӂ‡ÚÂθÌÓÒÚË ÔËÏÂÌËÚÂθÌÓ Í ‡Î„ÓËÚÏÛ î‡ÌÓ ÔÓÒΉӂ‡ÚÂθÌÓ„Ó ‰ÂÍÓ‰ËÓ‚‡ÌËfl Ò‚ÂÚÓ˜Ì˚ı ÍÓ‰Ó‚.ë‚ÂÚÓ˜Ì˚È ÍÓ‰ – ÍÓ‰ Ò ËÒÔ‡‚ÎÂÌËÂÏ Ó¯Ë·ÓÍ, ‚ ÍÓÚÓÓÏ Í‡Ê‰˚È k-·ËÚ ÔÓ‰ÎÂʇ˘Â„Ó ÍÓ‰ËÓ‚‡Ì˲ ËÌÙÓχˆËÓÌÌÓ„Ó ÒËςӷ ÔÂÓ·‡ÁÛÂÚÒfl ‚ n-·ËÚÓ‚ ÍÓ‰Ó‚ÓÂkÒÎÓ‚Ó, „‰Â R = ÂÒÚ¸ ÍÓ‰Ó‚‡fl ÒÍÓÓÒÚ¸ (n ≥ k), ‡ ÔÂÓ·‡ÁÓ‚‡ÌË – ÙÛÌ͈Ëfl ÔÓÒΉnÌËı m ËÌÙÓχˆËÓÌÌ˚ı ÒËÏ‚ÓÎÓ‚. ãËÌÂÈÌ˚È, Ì Á‡‚ËÒfl˘ËÈ ÓÚ ‚ÂÏÂÌË ‰ÂÍÓ‰Â(ÙËÍÒËÓ‚‡ÌÌ˚È Ò‚ÂÚÓ˜Ì˚È ‰ÂÍÓ‰Â) ÓÚÓ·‡Ê‡ÂÚ ËÌÙÓχˆËÓÌÌ˚È ÒËÏ‚ÓÎÉ·‚‡ 16. ê‡ÒÒÚÓflÌËfl ‚ ÚÂÓËË ÍÓ‰ËÓ‚‡ÌËfl253ui ∈{u1 ,..., u N }, ui = (ui1 ,..., uik ), uij ∈2 ÍÓ‰Ó‚Ó ÒÎÓ‚Ó xi ∈{x1 ,..., x N }, xi = ( xi1 ,..., xin ),xij ∈2 Ú‡ÍËÏ Ó·‡ÁÓÏ, ˜ÚÓ Ì‡ ‚˚ıӉ ÔÓÎÛ˜‡ÂÚÒfl ÍÓ‰ {x 1 ,..., xN} ËÁ N ÍÓ‰Ó‚˚ı ÒÎÓ‚ Ò‚ÂÓflÚÌÓÒÚflÏË {p( x1 ),..., p( x N )}.
èÓÒΉӂ‡ÚÂθÌÓÒÚ¸ l ÍÓ‰Ó‚˚ı ÒÎÓ‚ ÙÓÏËÛÂÚ ÔÓÚÓÍ (ËÎË ÔÛÚ¸) x = x[1, l ] = {x1 ,..., xl }, ÍÓÚÓ˚È Ô‰‡ÂÚÒfl ÔÓ ‰ËÒÍÂÚÌ˚ÏÍ‡Ì‡Î‡Ï ·ÂÁ Ô‡ÏflÚË Ë ÔÓÒÚÛÔ‡ÂÚ Ì‡ ÔËÂÏÌËÍ ‚ ‚ˉ ÔÓÒΉӂ‡ÚÂθÌÓÒÚË y = y[1,l].Ç Á‡‰‡˜Û ‰ÂÍӉ‡, Ô‰̇Á̇˜ÂÌÌÓ„Ó ‰Îfl ÏËÌËÏËÁ‡ˆËË ‚ÂÓflÚÌÓÒÚË Ó¯Ë·ÓÍ ‚ÔÓÒΉӂ‡ÚÂθÌÓÒÚË, ‚ıÓ‰ËÚ ÔÓËÒÍ ÔÓÒΉӂ‡ÚÂθÌÓÒÚË, ÍÓÚÓ‡fl χÍÒËχθÌÓÛ‚Â΢˂‡ÂÚ Ó·˘Û˛ ‚ÂÓflÚÌÓÒÚ¸ ‚ıÓ‰fl˘ÂÈ Ë ËÒıÓ‰fl˘ÂÈ ÔÓÒΉӂ‡ÚÂθÌÓÒÚÂÈp(x, y) = p (y | x) ⋅ p(x). é·˚˜ÌÓ ‰ÓÒÚ‡ÚÓ˜ÌÓ Ì‡ÈÚË Ôӈ‰ÛÛ Ï‡ÍÒËÏËÁ‡ˆËË p(y | x),Ë ‰ÂÍÓ‰Â, ‚Ò„‰‡ ‚˚·Ë‡˛˘ËÈ ‚ ͇˜ÂÒÚ‚Â Ò‚ÓÂÈ ÓˆÂÌÍË Ó‰ÌÛ ËÁ ÔÓÒΉӂ‡ÚÂθÌÓÒÚÂÈ, χÍÒËÏËÁËÛ˛˘Ëı ˝ÚÛ ‚Â΢ËÌÛ (ËÎË, ˝Í‚Ë‚‡ÎÂÌÚÌÓ, ÏÂÚË͇ î‡ÌÓ),̇Á˚‚‡ÂÚÒfl ‰ÂÍÓ‰ÂÓÏ Ï‡ÍÒËχθÌÓ„Ó Ô‡‚‰ÓÔÓ‰Ó·Ëfl.ÉÛ·Ó „Ó‚Ófl, ͇ʉ˚È ÍÓ‰ ÏÓÊÌÓ Ò˜ËÚ‡Ú¸ ‰Â‚ÓÏ, Û ÍÓÚÓÓ„Ó Í‡Ê‰‡fl ‚ÂÚ‚¸fl‚ÎflÂÚÒfl ÓÚ‰ÂθÌ˚Ï ÍÓ‰Ó‚˚Ï ÒÎÓ‚ÓÏ.
ÑÂÍӉ ̇˜Ë̇ÂÚ ‡·ÓÚÛ Ò Ô‚ÓÈ ‚¯ËÌ˚‰Â‚‡ Ë ‡ÒÒ˜ËÚ˚‚‡ÂÚ ÏÂÚËÍÛ ‚ÂÚ‚Ë ‰Îfl ͇ʉÓÈ ËÁ ‚ÓÁÏÓÊÌ˚ı ‚ÂÚ‚ÂÈ, ÓÔ‰ÂÎflflÍ‡Í Ì‡ËÎÛ˜¯Û˛ ÚÛ, ‚ÂÚ‚¸ ÍÓÚÓ‡fl ÒÓÓÚ‚ÂÚÒÚ‚ÛÂÚ ÍÓ‰Ó‚ÓÏÛ ÒÎÓ‚Û xj, ӷ·‰‡˛˘ÂÏÛ̇˷Óθ¯ÂÈ ÏÂÚËÍÓÈ ‚ÂÚ‚Ë µF(xj). ùÚ‡ ‚ÂÚ‚¸ ‰Ó·‡‚ÎflÂÚÒfl Í ÔÛÚË, Ë ‡Î„ÓËÚÏÔÓ‰ÓÎʇÂÚÒfl Ò ÌÓ‚ÓÈ ‚¯ËÌ˚, Ô‰ÒÚ‡‚Îfl˛˘ÂÈ ÒÛÏÏÛ Ô‰˚‰Û˘ÂÈ ‚¯ËÌ˚ ËÍÓ΢ÂÒÚ‚‡ ·ËÚÓ‚ ‚ ÚÂÍÛ˘ÂÏ Ì‡ËÎÛ˜¯ÂÏ ÍÓ‰Ó‚ÓÏ ÒÎÓ‚Â.èÓÒ‰ÒÚ‚ÓÏ ÔÓˆÂÒÒ‡ ËÚ‡ˆËË ‰Ó ÍÓ̘ÌÓÈ ‚¯ËÌ˚ ‰Â‚‡ ‡Î„ÓËÚÏ ÔÓÍ·‰˚‚‡ÂÚ Ì‡Ë·ÓΠ‚ÂÓflÚÌ˚È ÔÛÚ¸. Ç ˝ÚÓÏ ÔÓÒÚÓÂÌËË ·ËÚÓ‚‡fl ÏÂÚË͇ î‡ÌÓÓÔ‰ÂÎflÂÚÒfl ͇Ílog 2p( yi | xi )− R,p( yi )ÏÂÚË͇ ‚ÂÚ‚Ë î‡ÌÓ ÓÔ‰ÂÎflÂÚÒfl ͇ÍnµF (x j ) =p( yi | x ji )∑ log2p( yi )i =1− R ,‡ ÏÂÚË͇ ÔÛÚË î‡ÌÓ – ͇Ílµ F ( x[1, l ] ) =∑ µ F ( x j ),j =1„‰Â p( yi | x ji ) – ‚ÂÓflÚÌÓÒÚË ÔÂÂıÓ‰‡ ͇̇ÎÓ‚, p( yi ) =∑ p( xm )p( yi | xm ) – ‡ÒÔÂxm‰ÂÎÂÌË ‚ÂÓflÚÌÓÒÚÂÈ ‚˚ıÓ‰Ì˚ı ‰‡ÌÌ˚ı ÔË Á‡‰‡ÌÌ˚ı ‚ıÓ‰Ì˚ı ‰‡ÌÌ˚ı (ÛÒ‰kÌÂÌÌÓ ÔÓ ‚ÒÂÏ ‚ıÓ‰Ì˚Ï ÒËςӷÏ) Ë R = – ÍÓ‰Ó‚‡fl ÒÍÓÓÒÚ¸.n1ÑÎfl ‰ÂÍӉ‡ Ò "ÊÂÒÚÍËÏ" ¯ÂÌËÂÏ p( yi = 0 | x j = 0) = p, 0 < p <ÏÂÚËÍÛ2î‡ÌÓ ‰Îfl ÔÛÚË x[1, l ] ÏÓÊÌÓ Á‡ÔËÒ‡Ú¸ ͇͵ F ( x[1, l ] ) = −αd H ( y[1, l ] , x[1, l ] ) + β ⋅ l ⋅ n,„‰Â α = − log 2p> 0, β = 1 − R + log 2 (1 − p) Ë dH – ı˝ÏÏË̄ӂ‡ ÏÂÚË͇.1− p254ó‡ÒÚ¸ IV.
ê‡ÒÒÚÓflÌËfl ‚ ÔËÍ·‰ÌÓÈ Ï‡ÚÂχÚËÍÂé·Ó·˘ÂÌ̇fl ÏÂÚË͇ î‡ÌÓ ‰Îfl ÔÓÒΉӂ‡ÚÂθÌÓ„Ó ‰ÂÍÓ‰ËÓ‚‡ÌËfl ÓÔ‰ÂÎflÂÚÒfl ͇Íp( yi | x j ) wlog 21− w − wR ,p( y j )j =1 lnµ wF ( x[1, l ] ) =∑0 ≤ w ≤ 1. äÓ„‰‡ w = 1/2, Ó·Ó·˘ÂÌ̇fl ÏÂÚË͇ î‡ÌÓ Ò‚Ó‰ËÚÒfl Í ÏÂÚËÍ î‡ÌÓ ÒÏÛθÚËÔÎË͇ÚË‚ÌÓÈ ÍÓÌÒÚ‡ÌÚÓÈ 1/2.åÂÚ˘ÂÒ͇fl ÂÍÛÒËfl åÄê ‰ÂÍÓ‰ËÓ‚‡ÌËflå‡ÍÒËχθ̇fl ‡ÔÓÒÚÂËÓ̇fl ÓˆÂÌ͇ ÔÓÒΉӂ‡ÚÂθÌÓÒÚË ËÎË åÄê ‰ÂÍÓ‰ËÓ‚‡ÌË ‰Îfl ÍÓ‰Ó‚ ÔÂÂÏÂÌÌÓÈ ‰ÎËÌ˚, ËÒÔÓθÁÛ˛˘‡fl ‡Î„ÓËÚÏ ÇËÚ·Ë, ÓÒÌÓ‚‡Ì‡Ì‡ ÏÂÚ˘ÂÒÍÓÈ ÂÍÛÒËËΛ(km )=Λ(km−)1+l k( m )∑n =1x k( m, n) log 2p( yk , n | x k( m, n) = +1p( yk , n | x k( m, n) = −1+ 2 log 2 p(uk( m ) ),„‰Â Λ(km ) – ÏÂÚË͇ ‚ÂÚ‚Ë ‰Îfl ‚ÂÚ‚Ë m ‚ ÔÂËÓ‰ ‚ÂÏÂÌË (ÛÓ‚Â̸) k; xk,n – n-È ·ËÚ ÍÓ‰Ó‚Ó„Ó ÒÎÓ‚‡ Ò lk( m ) ·ËÚ‡ÏË, ÔÓϘÂÌÌ˚ı ̇ ͇ʉÓÈ ‚ÂÚ‚Ë; Ûk,n – ÒÓÓÚ‚ÂÚÒÚ‚Û˛˘ËÈÔËÌflÚ˚È "Ïfl„ÍËÈ" ·ËÚ; ukm – ËÒıÓ‰Ì˚ ÒËÏ‚ÓÎ˚ ‚ÂÚ‚Ë m ‚ ÔÂËÓ‰ k, Ë ÔËÔ‰ÔÓÎÓÊÂÌËË ÒÚ‡ÚËÒÚ˘ÂÒÍÓÈ ÌÂÁ‡‚ËÒËÏÓÒÚË ËÒıÓ‰Ì˚ı ÒËÏ‚ÓÎÓ‚ ‚ÂÓflÚÌÓÒÚ¸p(uk( m ) ) ˝Í‚Ë‚‡ÎÂÌÚ̇ ‚ÂÓflÚÌÓÒÚË ËÒıÓ‰ÌÓ„Ó ÒËςӷ, ÔÓϘÂÌÌÓ„Ó Ì‡ ‚ÂÚ‚Ë m,ÍÓÚÓ‡fl ËÁ‚ÂÒÚ̇ ËÎË ‡ÒÒ˜ËÚ˚‚‡ÂÚÒfl.
åÂÚ˘ÂÒÍËÈ ËÌÍÂÏÂÌÚ ‡ÒÒ˜ËÚ˚‚‡ÂÚÒfl‰Îfl ͇ʉÓÈ ‚ÂÚ‚Ë, Ë Ì‡Ë·Óθ¯Â Á̇˜ÂÌËÂ, ÔË ËÒÔÓθÁÓ‚‡ÌËË ÎÓ„‡ËÙÏ˘ÂÒÍÓ„ÓÁ̇˜ÂÌËfl Ô‡‚‰ÓÔÓ‰Ó·Ëfl Í‡Ê‰Ó„Ó ÒÓÒÚÓflÌËflËÒÔÓθÁÛÂÚÒfl ‰Îfl ‰‡Î¸ÌÂȯÂÈ ÂÍÛÒËË. ÑÂÍӉ Ò̇˜‡Î‡ ‚˚˜ËÒÎflÂÚ ÏÂÚËÍÛ Ì‡ ‚ÒÂı ‚ÂÚ‚flı, Ë Á‡ÚÂÏ ÒÓÓÚ‚ÂÚÒÚ‚Û˛˘‡fl ÔÓÒΉӂ‡ÚÂθÌÓÒÚ¸ Ò Ì‡Ë·Óθ¯ÂÈ ÏÂÚËÍÓÈ ‚ÂÚ‚Ë ‚˚·Ë‡ÂÚÒfl ̇˜Ë̇flÒ Á‡Íβ˜ËÚÂθÌÓ„Ó ÒÓÒÚÓflÌËfl.É·‚‡ 17êÄëëíéüçàü à èéÑéÅçéëíàÇ ÄçÄãàáÖ ÑÄççõïåÌÓÊÂÒÚ‚Ó ‰‡ÌÌ˚ı – ÍÓ̘ÌÓ ÏÌÓÊÂÒÚ‚Ó, ÒÓÒÚÓfl˘Â ËÁ m ÔÓÒΉӂ‡ÚÂθÌÓÒÚÂÈ( x1j ,..., x nj ), j ∈{1,..., m} ‰ÎËÌ˚ n. á̇˜ÂÌËfl xi1 ,..., xim Ô‰ÒÚ‡‚Îfl˛Ú ‡ÚË·ÛÚ S i.éÌ ÏÓÊÂÚ ·˚Ú¸ ˜ËÒÎÓ‚˚Ï, ‚ ÚÓÏ ˜ËÒΠÌÂÔÂ˚‚Ì˚Ï (‰ÂÈÒÚ‚ËÚÂθÌ˚ ˜ËÒ·) ˉ‚Ó˘Ì˚Ï (‰‡/ÌÂÚ ‚˚‡Ê‡ÂÚÒfl Í‡Í 1/0), Ó‰Ë̇θÌ˚Ï (˜ËÒ·ÏË Û͇Á˚‚‡ÂÚÒfl ÚÓθÍӇ̄) ËÎË ÌÓÏË̇θÌ˚Ï (ÌÂÛÔÓfl‰Ó˜ÂÌÌ˚Ï).ä·ÒÚÂÌ˚È ‡Ì‡ÎËÁ (ËÎË Í·ÒÒËÙË͇ˆËfl, Ú‡ÍÒÓÌÓÏËfl, ‡ÒÔÓÁ̇‚‡ÌË ӷ‡ÁÓ‚)Ô‰ÒÚ‡‚ÎflÂÚ ÒÓ·ÓÈ ‡Á·ËÂÌË ‰‡ÌÌ˚ı Ä Ì‡ ÓÚÌÓÒËÚÂθÌÓ Ï‡ÎÓ ˜ËÒÎÓ Í·ÒÚÂÓ‚,Ú.Â.
Ú‡ÍËı ÏÌÓÊÂÒÚ‚ Ó·˙ÂÍÚÓ‚, ˜ÚÓ (ÔÓ ÓÚÌÓ¯ÂÌ˲ Í ‚˚·‡ÌÌÓÈ Ï ‡ÒÒÚÓflÌËfl)Ó·˙ÂÍÚ˚, ̇ÒÍÓθÍÓ ˝ÚÓ ‚ÓÁÏÓÊÌÓ, "·ÎËÁÍË", ÂÒÎË ÔË̇‰ÎÂÊ‡Ú Ó‰ÌÓÏÛ Ë ÚÓÏÛ ÊÂÍ·ÒÚÂÛ, Ë "‰‡ÎÂÍË", ÂÒÎË ÔË̇‰ÎÂÊ‡Ú ‡ÁÌ˚Ï Í·ÒÚ‡Ï, Ë ‰‡Î¸ÌÂȯ ÔÓ‰‡Á‰ÂÎÂÌË ̇ Í·ÒÚÂ˚ ÓÒ··ËÚ ‚˚¯ÂÛ͇Á‡ÌÌ˚ ÛÒÎÓ‚Ëfl.ê‡ÒÒÏÓÚËÏ ÚË ÚËÔ˘Ì˚ı ÒÎÛ˜‡fl. Ç ÔËÎÓÊÂÌËflı, Ò‚flÁ‡ÌÌ˚ı Ò ‚˚·ÓÍÓÈ ËÌÙÓχˆËË, ÛÁÎ˚ Ó‰ÌӇ̄ӂÓÈ ·‡Á˚ ‰‡ÌÌ˚ı ˝ÍÒÔÓÚËÛ˛Ú ËÌÙÓχˆË˛ (ÒÓ‚ÓÍÛÔÌÓÒÚ¸ ÚÂÍÒÚÓ‚˚ı ‰ÓÍÛÏÂÌÚÓ‚); ͇ʉ˚È ‰ÓÍÛÏÂÌÚ ı‡‡ÍÚÂËÁÛÂÚÒfl ‚ÂÍÚÓÓÏ ËÁn. Ç Á‡ÔÓÒ ÔÓθÁÓ‚‡ÚÂÎfl ÒÓ‰ÂÊËÚÒfl ‚ÂÍÚÓ x ∈ n, Ë ÔÓθÁÓ‚‡ÚÂβ ÌÂÓ·ıÓ‰ËÏ˚‚Ò ‰ÓÍÛÏÂÌÚ˚ ·‡Á˚ ‰‡ÌÌ˚ı, Ëϲ˘Ë ÓÚÌÓ¯ÂÌËÂ Í ˝ÚÓÏÛ Á‡ÔÓÒÛ, Ú.Â. ÔË̇‰ÎÂʇ˘Ë ¯‡Û ‚ n Ò ˆÂÌÚÓÏ ‚ ı, ÙËÍÒËÓ‚‡ÌÌÓ„Ó ‡‰ËÛÒ‡ Ë ÔÓ‰ıÓ‰fl˘ÂÈÙÛÌ͈ËÂÈ ‡ÒÒÚÓflÌËfl.
Ç „ÛÔÔËÓ‚Í Á‡ÔËÒÂÈ, ͇ʉ˚È ‰ÓÍÛÏÂÌÚ (Á‡ÔËÒ¸ ‚ ·‡Á‰‡ÌÌ˚ı) Ô‰ÒÚ‡‚ÎÂÌ ‚ÂÍÚÓÓÏ ˜‡ÒÚÓÚÌÓÒÚË ÚÂÏË̇ x ∈ n , Ë Ú·ÛÂÚÒfl ÓÔ‰ÂÎËÚ¸ ÒÂχÌÚ˘ÂÒÍÛ˛ Á̇˜ËÏÓÒÚ¸ ÒËÌÚ‡ÍÒ˘ÂÒÍË ‡ÁÌ˚ı Á‡ÔËÒÂÈ. Ç ˝ÍÓÎÓ„ËË, ÂÒÎË‚ÂÍÚÓ‡ ı, Û Ó·ÓÁ̇˜‡˛Ú ‡ÒÔ‰ÂÎÂÌËfl ˜ËÒÎÂÌÌÓÒÚË ‚ˉӂ, ÔÓÎÛ˜ÂÌÌ˚ ‰‚ÛÏflÏÂÚÓ‰‡ÏË, ‚˚·ÓÍË ‰‡ÌÌ˚ı (Ú.Â. x j, yj – ˜ËÒ· Ë̉˂ˉӂ ‚ˉ‡ j, ÔÓÎÛ˜ÂÌÌ˚ ‚ÒÓÓÚ‚ÂÚÒÚ‚Û˛˘ÂÈ ‚˚·ÓÍÂ), ÚÓ Ú·ÛÂÚÒfl ÓÔ‰ÂÎËÚ¸ ÏÂÛ ‡ÒÒÚÓflÌËfl ÏÂÊ‰Û ı Ë Û‰Îfl Ò‡‚ÌÂÌËfl ‰‚Ûı ÏÂÚÓ‰Ó‚.
ᇘ‡ÒÚÛ˛ ‰‡ÌÌ˚ ӄ‡ÌËÁÛ˛ÚÒfl Ò̇˜‡Î‡ ‚ ‚ˉÂÏÂÚ˘ÂÒÍÓ„Ó ‰Â‚‡, Ú.Â. ‚ ‚ˉ ‰Â‚‡, Ë̉ÂÍÒËÓ‚‡ÌÌÓ„Ó ˝ÎÂÏÂÌÚ‡ÏË ÏÂÚ˘ÂÒÍÓ„Ó ÔÓÒÚ‡ÌÒÚ‚‡.èÓÒΠ‚˚·Ó‡ ‡ÒÒÚÓflÌËfl d ÏÂÊ‰Û Ó·˙ÂÍÚ‡ÏË ÏÂÚË͇ ÎËÌÍˉʇ, Ú.Â. ‡ÒÒÚÓflÌË ÏÂÊ‰Û Í·ÒÚ‡ÏË A = {a 1 ,..., am} Ë B = {b1 ,..., bn }, Ó·˚˜ÌÓ ÓÔ‰ÂÎflÂÚÒfl ͇ÍÓ‰ÌÓ ËÁ ÒÎÂ‰Û˛˘Ëı:– ÛÒ‰ÌÂÌ̇fl ÎËÌÍˉÊ: ҉̠Á̇˜ÂÌË ‡ÒÒÚÓflÌËÈ ÏÂÊ‰Û ‚ÒÂÏË ˜ÎÂ̇ÏËd ( ai , b j )∑∑˝ÚËı Í·ÒÚÂÓ‚, Ú.Â.ij;mn– Ó‰Ë̇Ì˚È ÎËÌÍˉÊ: ‡ÒÒÚÓflÌË ÏÂÊ‰Û ·ÎËʇȯËÏË ˜ÎÂ̇ÏË ˝ÚËı Í·ÒÚÂÓ‚,Ú.Â. min d ( ai , b j );ij– ÔÓÎÌ˚È ÎËÌÍˉÊ: ‡ÒÒÚÓflÌË ÏÂÊ‰Û Ò‡Ï˚ÏË Û‰‡ÎÂÌÌ˚ÏË ‰Û„ ÓÚ ‰Û„‡˜ÎÂ̇ÏË ˝ÚËı Í·ÒÚÂÓ‚, Ú.Â. min d ( ai , b j );ij256ó‡ÒÚ¸ IV.
ê‡ÒÒÚÓflÌËfl ‚ ÔËÍ·‰ÌÓÈ Ï‡ÚÂχÚËÍ– ÎËÌÍË‰Ê ˆÂÌÚÓˉӂ: ‡ÒÒÚÓflÌË ÏÂÊ‰Û ˆÂÌÚÓˉ‡ÏË (ˆÂÌÚ‡ÏË ÚflÊÂÒÚË)aibiii˜˝ÚËı Í·ÒÚÂÓ‚, Ú.Â. || a˜ − b ||2 , „‰Â a =Ë b=;mnmin|| a˜ − b˜ ||2 .– ÎËÌÍË‰Ê ‚‡‰‡: ‡ÒÒÚÓflÌËÂm+nåÌÓ„ÓÏÂÌÓ ¯Í‡ÎËÓ‚‡ÌË – ÚÂıÌË͇, ÔËÏÂÌflÂχfl ‚ ӷ·ÒÚË Ôӂ‰Â̘ÂÒÍËı ËÒӈˇθÌ˚ı ̇ÛÍ ‰Îfl ËÒÒΉӂ‡ÌËfl Ó·˙ÂÍÚÓ‚ ËÎË Î˛‰ÂÈ. ÇÏÂÒÚÂ Ò Í·ÒÚÂÌ˚χ̇ÎËÁÓÏ Ó̇ ·‡ÁËÛÂÚÒfl ̇ ËÒÔÓθÁÓ‚‡ÌËË ‡ÒÒÚÓflÌËÈ. é‰Ì‡ÍÓ ÔË ÏÌÓ„ÓÏÂÌÓϯ͇ÎËÓ‚‡ÌËË, ‚ ÓÚ΢ˠÓÚ Í·ÒÚÂÌÓ„Ó ‡Ì‡ÎËÁ‡, ÔÓˆÂÒÒ Ì‡˜Ë̇ÂÚÒfl Ò ÌÂÍÓÚÓÓÈm × m χÚˈ˚ D ‡ÒÒÚÓflÌËÈ ÏÂÊ‰Û Ó·˙ÂÍÚ‡ÏË Ë Á‡ÚÂÏ (ËÚ‡ˆËÓÌÌÓ) ˢÂÚÒflÂÔÂÁÂÌÚ‡ˆËfl Ó·˙ÂÍÚÓ‚ ‚ n Ò Ï‡Î˚Ï n, ڇ͇fl ˜ÚÓ Ëı χÚˈ‡ ‚ÍÎˉӂ˚ı ‡ÒÒÚÓflÌËÈ ËÏÂÂÚ ÏËÌËχθÌÓ ͂‡‰‡Ú˘ÌÓ ÓÚÍÎÓÌÂÌË ÓÚ ËÒıÓ‰ÌÓÈχÚˈ˚ D.Ç ÔÓˆÂÒÒ ‡Ì‡ÎËÁ‡ ‰‡ÌÌ˚ı ÔËÏÂÌfl˛ÚÒfl ÏÌÓ„Ë ÔÓ‰Ó·ÌÓÒÚË; Ëı ‚˚·Ó Á‡‚ËÒËÚÓÚ ı‡‡ÍÚ‡ ‰‡ÌÌ˚ı Ë ÔÓ͇ ÚÓ˜ÌÓÈ Ì‡ÛÍÓÈ Ì fl‚ÎflÂÚÒfl.
çËÊ Ô˂ӉflÚÒflÓÒÌÓ‚Ì˚ ËÁ ˝ÚËı ÔÓ‰Ó·ÌÓÒÚÂÈ Ë ‡ÒÒÚÓflÌËÈ.ÑÎfl ‰‚Ûı Ó·˙ÂÍÚÓ‚, Ô‰ÒÚ‡‚ÎÂÌÌ˚ı ÌÂÌÛ΂˚ÏË ‚ÂÍÚÓ‡ÏË x = (x 1 ,..., x n ) Ëy = (y 1 ,..., yn) ËÁ n, ‚ ‰‡ÌÌÓÈ „·‚ ËÒÔÓθÁÛ˛ÚÒfl ÒÎÂ‰Û˛˘Ë ӷÓÁ̇˜ÂÌËfl:∑∑∑nxi ÓÁ̇˜‡ÂÚ∑ xi .i =11 F – ı‡‡ÍÚÂËÒÚ˘ÂÒ͇fl ÙÛÌ͈Ëfl ÒÓ·˚ÚËfl F: 1 F = 1, ÂÒÎË F ËÏÂÂÚ ÏÂÒÚÓ Ë1F = 0, ÂÒÎË ÌÂÚ.|| x ||2 = ∑ xi2 – Ó·˚˜Ì‡fl ‚ÍÎˉӂ‡ ÌÓχ ̇ n.∑ xi1, Ú.Â.