Yapafupi mnansi njira: chitsanzo cha ntchito

yapafupi mnansi njira ndi zovuta chinkafunika classifier zomwe zachokera aziona kufanana kwa zinthu zosiyanasiyana.

Kusanthula chinthu wa kalasi imene iwo ali nzika za maphunziro nyemba. Tiyeni tione omwe ndi anzathu yapafupi. Yesetsani kumvetsa nkhani yovuta zitsanzo za maluso osiyanasiyana.

njira kungoganizira

yapafupi njira mnansi tinganene kuti ngati aligorivimu ambiri ntchito gulu. Chinthu likufa gulu wa y_i kalasi, kumene chinthu wapafupi kuphunzira x_i nyemba.

Kulunjika njira yapafupi anansi

a k yapafupi mnansi njira kusintha yolondola gulu. Kusanthula chinthu limabweretsa m'kalasi lomwelo ngati zambiri za anansi ake, ndiko kuti, K pafupi ndi iye akutsutsa za kusanthula chitsanzo x_i. Kuthetsa mavuto ndi osiyana chiwerengero cha anthu oyandikana adzakhala osamvetseka kwa kupewa zinthu za ambiguity, ngati nambalayi wa anansi zidzakhala za magulu osiyanasiyana.

Njira oyandikana inaimitsidwa

Postgresql-kusanthula njira tsvector yapafupi anansi ntchito pamene nambala maphunziro osachepera atatu, ndipo iwe sungakhoze ntchito nambala wosamvetseka. Koma ambiguity n'lakuti ngakhale mu milandu. Ndiye, i-TH mnansi afika w_i kulemera, amene amachepetsa ndi udindo mnansi i. Zimatanthauza kalasi wa chinthu, umene ndi pazipita okwana kulemera mwa anansi pafupi.

The amanena za compactness

Pa mtima wa onse njira pamwamba ndi kungoganizira za compactness. Ikutchula kugwirizana pakati pa muyeso wa kufanana kwa zinthu ndi wachokera awo m'kalasi lomwelo. Imeneyi, malire pakati pa mitundu yosiyanasiyana ndi mawonekedwe ophweka, ndi kulenga makalasi a zinthu mu malo yaying'ono m'dera yam'manja. Pansi mbali zoterozo mu kusanthula masamu zimatanthawuza kuti chatsekedwa njanjira akonzedwa. kungoganizira Izi sizikugwirizana ndi maganizo tsiku ndi tsiku mawu.

Chilinganizo zoyambirira

Tiyeni tione zina yapafupi anzathu. Ngati akufuna kuphunzira chitsanzo mtundu "chinthu-ayankhe» X ^ mamita = \ {(x_1, y_1), \ madontho, (x_m, y_m) \}; ngati kuchuluka kwa zinthu kuthandauza mtunda ntchito \ rho (×, x '), amene akuimira mu mawonekedwe a chokwanira chitsanzo kufanana kwa zinthu ndi kuwonjezera phindu la kugwira ntchito amachepetsa kufanana pakati pa zinthu ×, x'.

Pakuti chinthu chilichonse, u adzamange maphunziro chitsanzo akutsutsa x_i ndi kuwonjezeka kutalika kwa u:

\ Rho (u, x_ {1; u}) \ leq \ rho (u, x_ {2; u}) \ leq \ cdots \ leq \ rho (u, x_ {mamita; u}),

kumene x_ {ine; u} amadziwika chinthu kuphunzira nyemba, zomwe ndi i-TH mnansi gwero chinthu u. Chotero kalembedwe ndi ntchito kumuyankha i-TH mnansi: y_ {ine; u}. Chifukwa, ife tikupeza kuti chinthu chilichonse u amakwiya renumbering nyemba zokha.

Khama la nambala K wa anansi

yapafupi mnansi njira pamene K = 1 amatha kupereka gulu olakwika, osati pa zinthu-mpweya, komanso magulu ena amene ali pafupi.

Ngati timatenga a k = m, ndi aligorivimu adzakhala wosasunthika ndipo pokhala mtengo nthawi zonse. N'chifukwa chake kudalirika N'kofunika kupewa akalozera kwambiri a k.

Zochita ngati mulingo woyenera index K ntchito muyezo kutsetsereka kulamulira.

screenings mpweya

The zinthu kuphunzira kwakukulukulu wosiyana, koma mwa iwo pali ena amene ali ndi makhalidwe a kalasi ndipo amatchedwa mfundo. Pa moyandikana a nkhani za chitsanzo yabwino Mwina ake okwezeka anthu a kalasi.

Kodi rezultativen njira oyandikana yapafupi? Chitsanzo Tingaone pa maziko a magulu zotumphukira ndipo sanali zothandiza pa zinthu. Amaganiza chilengedwe wandiweyani wa chinthu oimira ena a kalasi. Pamene inu kuwachotsa gulu la zitsanzo zosankhidwazi khalidwe sadzalola.

Kulowa nambala inayake zitsanzo phokoso mulole bursts kuti ndi "pansi" a kalasi. Kuchotsa amadza zayamba zabwino pa khalidwe la gulu la.

Ngati chitsanzo anatengedwa kuchokera uninformative ndi kuthetsa zinthu phokoso, yembekezerani pa zotsatira zochepa zabwino nthawi yomweyo.

Woyamba sanaike njira yapafupi mnansi gulu zimathandiza kupititsa patsogolo quality, kuchepetsa deta kusungidwa, kuchepetsa nthawi ya gulu, amene anakhala pa kusankha mfundo yotsatira.

Kugwiritsa ntchito zitsanzo kopitilira muyeso-chachikulu

yapafupi njira mnansi zochokera yosungirako chenicheni cha zinthu kuphunzira. Kulenga kwambiri zitsanzo zikuluzikulu ntchito vuto linalake. cholinga Osangopereka kupulumutsa kwambiri kuchuluka kwa mfundo, komanso osachepera kuchuluka kwa nthawi ndi nthawi kupeza chinthu chilichonse u a k mwa anansi apamtima.

Pofuna kuchepetsa ntchito imeneyi, njira ziwiri ntchito:

• thinned chitsanzo kudzera ndi zinthu kumaliseche sanali deta;
• ogwira ntchito yapadera deta kapangidwe ndi zizindikiro pakusaka nthawi ya oyandikana yapafupi.

Malamulo a njira yosankhira

Gulu pamwamba ankaona. Yapafupi mnansi njira ntchito pothetsa mavuto othandiza, omwe amadziwika pasadakhale mtunda ntchito \ rho (×, x '). Pofotokoza zinthu zamoyo zina M'ndandanda ntchito chinkafunika Euclidean. kusankha Palibe kulungamitsidwa wapadera, koma kumafuna muyeso wa zizindikiro zonse "mu muyezo wofanana." Ngati chinthu ichi si n'komwe, ndiye chinkafunika adzakhala amachuluka mbali ndi makhalidwe apamwamba M'ndandanda.

Ngati pali ndalama zochuluka zizindikiro kuwerengetsa mtunda monga Uwerenge zolakwika pa zizindikiro zenizeni kuoneka vuto lalikulu gawo.

Mu malo okwezeka ooneka enieni kutali kwa mnzake adzathedwa zinthu. Potsilizira pake, nyemba aliyense adzakhala pafupi chinthu akuphunziridwa K anansi. anasankha ochepa mbali nkhani kuthetsa vutoli. Ma aligorivimu kwa kuwerengetsa Ziwerengero kumanga pa maziko kukukhala yosiyanasiyana ya zizindikiro ndi aliyense kumanga moyandikana awo ntchito.

Pomaliza

masamu zambiri zimagwiritsa ntchito zosiyanasiyana njira kuti ali zawo zapadera makhalidwe, ubwino ndi kuipa. Ankaona yapafupi mnansi njira angathetse ndithu vuto lalikulu, chifukwa maonekedwe a zinthu masamu. Lingaliro komanso zochokera njira kusanthula akugwiritsa ntchito mwakhama nzeru zochita kupanga.

M'magulu Mkuluyo m'pofunika osati m'kagulu zinthu, komanso kusonyeza wosuta mumve za gulu funso. Mu njira imeneyi, kulongosola zodabwitsazi ali anasonyeza poyerekezera ndi chinthu kalasi ina komanso malo wachibale chitsanzo ntchito. Malamulo makampani akatswiri, Akatswiriwa, madokotala, kutenga ichi "zachilendo" mfundo mwakhama ntchito mu kafukufuku wawo.

Kuti kusanthula njira anali yodalirika, imayenera kupereka zotsatira anakhumba, utenge osachepera chithunzi K, komanso kupewa mpweya mwa zinthu kusanthula kale. Ndicho chifukwa chake ntchito mfundo ndi njira yosankhira, komanso zokhazikitsidwa kukhathamiritsa.