Cholinga cha nkhaniyi ndikupereka chithandizo kwa asayansi oyambira deta. MU
Chifukwa chake ndizomveka kumvetsera kwambiri chilinganizo ?
Ndi ndi matrix equation kuti nthawi zambiri munthu amayamba kuzolowerana ndi mzere wobwerera. Panthawi imodzimodziyo, kuwerengera mwatsatanetsatane momwe formula inapangidwira ndizosowa.
Mwachitsanzo, m'maphunziro ophunzirira makina kuchokera ku Yandex, ophunzira akadziwitsidwa kukhazikika, amaperekedwa kuti agwiritse ntchito ntchito kuchokera ku library. dziwa, pomwe palibe mawu omwe amatchulidwa okhudza matrix oyimira algorithm. Ndi panthawiyi pomwe omvera ena angafune kumvetsetsa nkhaniyi mwatsatanetsatane - lembani kachidindo popanda kugwiritsa ntchito zomwe zapangidwa kale. Ndipo kuti muchite izi, choyamba muyenera kuwonetsa equation ndi chokhazikika mu mawonekedwe a matrix. Nkhaniyi ipereka mwayi kwa omwe akufuna kudziwa luso lotere. Tiyeni tiyambe.
Mikhalidwe yoyambirira
Zizindikiro za zomwe mukufuna
Tili ndi zinthu zingapo zomwe tikufuna. Mwachitsanzo, chizindikiro chandamale chikhoza kukhala mtengo wazinthu zilizonse: mafuta, golide, tirigu, dola, ndi zina. Pa nthawi yomweyo, ndi chiwerengero cha chandamale chandamale mfundo timatanthawuza chiwerengero cha zowonera. Zowona zotere zitha kukhala, mwachitsanzo, mitengo yamafuta pamwezi pachaka, ndiye kuti, tidzakhala ndi 12 zomwe tikufuna. Tiyeni tiyambe kuyambitsa notation. Tiyeni tiwone mtengo uliwonse wa chizindikiro chandamale ngati . Zonse tili nazo zowonera, zomwe zikutanthauza kuti titha kuyimira zomwe tikuwona ngati .
Obwerera
Tidzaganiza kuti pali zinthu zomwe zimafotokozera pamlingo wina zomwe zikuwonetsa zomwe mukufuna. Mwachitsanzo, ndalama za dollar / ruble zimakhudzidwa kwambiri ndi mtengo wa mafuta, Federal Reserve rate, etc. Zinthu zoterezi zimatchedwa regressors. Panthawi imodzimodziyo, mtengo uliwonse wamtengo wapatali uyenera kufanana ndi mtengo wa regressor, ndiye kuti, ngati tili ndi zizindikiro 12 za mwezi uliwonse mu 2018, ndiye kuti tiyeneranso kukhala ndi 12 regressor values ββnthawi yomweyo. Tiyeni tifotokozere za regressor iliyonse ndi . Kwa ife pakhale regressors (ie. zinthu zomwe zimakhudza zilolezo zowunikira). Izi zikutanthauza kuti ma regressors athu atha kuperekedwa motere: kwa 1st regressor (mwachitsanzo, mtengo wamafuta): , kwa 2nd regressor (mwachitsanzo, Fed rate): , Za "-th" regressor:
Kudalira kwa zizindikiro zomwe zikuyang'aniridwa pa regressors
Tiyerekeze kuti kudalira chizindikiro chandamale kuchokera ku regressors "th" kuyang'ana kungasonyezedwe kupyolera mu mzere wobwerezabwereza wa mawonekedwe:
kumene - "-th" mtengo wa regressor kuchokera ku 1 mpaka ,
- chiwerengero cha regressors kuchokera 1 mpaka
- ma coefficients aang'ono, omwe amaimira kuchuluka komwe chizindikiro chowerengera chidzasintha pafupifupi pamene regressor ikusintha.
Mwanjira ina, ndife a aliyense (kupatulapo ) ya regressor timasankha "zathu" coefficient , kenaka chulukitsani ma coefficients ndi ma regressors "th" kuwunika, chifukwa chake timapeza pafupifupi "-th" chizindikiro chandamale.
Chifukwa chake, tiyenera kusankha ma coefficients oterowo , pomwe mayendedwe athu oyandikira amagwira ntchito idzakhala pafupi kwambiri ndi zizindikiro zomwe mukufuna.
Kuwunika mtundu wa ntchito yoyandikira
Tidzazindikira kuwunika kwa ntchito yoyandikira pogwiritsa ntchito njira ya ma squares ochepa. Ntchito yowunika bwino pankhaniyi itenga mawonekedwe awa:
Tiyenera kusankha zikhalidwe zotere za coefficients $w$ zomwe mtengo wake adzakhala wamng'ono kwambiri.
Kutembenuza equation kukhala mawonekedwe a matrix
Chiwonetsero cha Vector
Poyamba, kuti moyo wanu ukhale wosavuta, muyenera kulabadira mizere yosinthira equation ndikuzindikira kuti coefficient yoyamba. sikuchulukitsidwa ndi regressor iliyonse. Panthawi imodzimodziyo, tikasintha deta kukhala mawonekedwe a matrix, zochitika zomwe tatchulazi zidzasokoneza kwambiri kuwerengera. Pachifukwa ichi, akufunsidwa kuti awonetsere regressor wina wa coefficient yoyamba ndikufananiza ndi chimodzi. Kapena, aliyense "yerekezerani mtengo wa regressor iyi ndi imodzi - pambuyo pake, ikachulukitsidwa ndi imodzi, palibe chomwe chidzasinthe kuchokera pakuwona zotsatira za kuwerengera, koma kuchokera pamalingaliro a malamulo opangira matrices, mazunzo athu. zidzachepetsedwa kwambiri.
Tsopano, pakadali pano, kuti tifewetse zinthuzo, tiyeni tiyerekeze kuti tili ndi imodzi yokha "-th" kuwona. Kenako, taganizirani zamtengo wapatali za regressors "-th" zowonera ngati vekitala . Vector ali ndi dimension , ndiko mizere ndi 1 ndime:
Tiyeni tiyimire ma coefficients ofunikira ngati vekitala , kukhala ndi dimension :
Linear regression equation ya "-th" kuyang'ana kudzatenga mawonekedwe:
Ntchito yowunika mtundu wamtundu wa mzere itenga mawonekedwe:
Chonde dziwani kuti molingana ndi malamulo akuchulutsa matrix, tidafunikira kusinthira vekitala .
Chiwonetsero cha matrix
Chifukwa cha kuchuluka kwa ma vectors, timapeza nambala: , zomwe ziyenera kuyembekezera. Nambala iyi ndiye kuyerekezera "-th" chizindikiro chandamale. Koma tifunika kuyerekeza osati mtengo umodzi wokha, koma onsewo. Kuti tichite izi, lembani zonse "-th" ma regressors mumtundu wa matrix . Zotsatira zake zimakhala ndi kukula kwake :
Tsopano linear regression equation itenga mawonekedwe:
Tiwonetseni zomwe zikuwonetsa zomwe mukufuna (zonse ) pa vector dimension :
Tsopano titha kulemba equation kuti tiwunikire mtundu wa mzere wa mzere mumtundu wa matrix:
Kwenikweni, kuchokera mu formula iyi timapezanso fomula yomwe tikudziwa
Kodi zachitika bwanji? Mabakiteriya amatsegulidwa, kusiyanitsa kukuchitika, mawu otulukawo amasinthidwa, etc., ndipo izi ndi zomwe tidzachita tsopano.
Kusintha kwa matrix
Tiyeni titsegule mabulaketi
Tiyeni tikonzekere equation kuti tisiyanitse
Kuti tichite izi, tidzasintha zina. M'mawerengedwe otsatirawa zidzakhala zosavuta kwa ife ngati vekitala idzayimiridwa kumayambiriro kwa chinthu chilichonse mu equation.
Kutembenuka 1
Zinachitika bwanji? Kuti muyankhe funsoli, ingoyang'anani kukula kwa matrices omwe akuchulukitsidwa ndikuwona kuti pakutulutsa timapeza nambala kapena ayi. .
Tiyeni tilembe kukula kwa mawu a matrix.
Kutembenuka 2
Tiyeni tilembe mofanana ndi kusintha 1
Pazotulutsa timapeza equation yomwe tiyenera kusiyanitsa:
Timasiyanitsa ntchito yowunikira khalidwe lachitsanzo
Tiyeni tisiyanitse polemekeza vekitala :
Mafunso chifukwa sipayenera kukhala, koma tiwona momwe tingagwiritsire ntchito kudziwa zotumphukira m'mawu ena awiriwo mwatsatanetsatane.
Kusiyana 1
Tiyeni tiwonjezere pa kusiyanasiyana:
Kuti mudziwe zomwe zimachokera ku matrix kapena vector, muyenera kuyang'ana zomwe zili mkati mwake. Tiyeni tiwone:
Tiyeni tifotokozere za matrices kudzera pa matrix . Matrix square ndi kuwonjezera apo, ndi symmetrical. Zinthu izi zitha kukhala zothandiza kwa ife pambuyo pake, tizikumbukira. Matrix ali ndi dimension :
Tsopano ntchito yathu ndikuchulutsa ma vectors moyenera ndi matrix osapeza "kawiri kawiri ndi kasanu," kotero tiyeni tilingalire ndikusamala kwambiri.
Komabe, tapeza mawu ovuta! M'malo mwake, tili ndi nambala - scalar. Ndipo tsopano, kwenikweni, timapita ku kusiyanitsa. Ndikofunikira kupeza chotengera cha mawu omwe amachokera pa coefficient iliyonse ndi kupeza dimension vector monga zotuluka . Zikatero, ndilemba ndondomeko ndikuchita:
1) kusiyanitsa ndi , timapeza:
2) kusiyanitsa ndi , timapeza:
3) kusiyanitsa ndi , timapeza:
Zomwe zimatuluka ndi vector yolonjezedwa ya kukula :
Ngati muyang'ana kwambiri vekitalayo, mudzazindikira kuti zinthu zakumanzere ndi zofananira za vector zitha kuikidwa m'magulu kuti, chifukwa chake, vekitala ikhoza kupatulidwa kuchokera ku vector yomwe yaperekedwa. kukula . Mwachitsanzo, (chinthu chakumanzere cha mzere wapamwamba wa vector) (chinthu choyenera cha mzere wapamwamba wa vekitala) chikhoza kuimiridwa ngati ndi - monga ndi zina. pa mzere uliwonse. Tiyeni tipange gulu:
Tiyeni titulutse vekitala ndipo pamapeto pake timapeza:
Tsopano, tiyeni tione mwatsatanetsatane zotsatira zake masanjidwewo. Matrix ndi kuchuluka kwa matrices awiri :
Tikumbukire kuti m'mbuyomu tidawona chinthu chimodzi chofunikira cha matrix - ndi symmetrical. Zochokera katundu, tikhoza kunena molimba mtima kuti mawu ofanana . Izi zitha kutsimikiziridwa mosavuta ndikukulitsa zinthu za matrices ndi chinthu . Sitidzachita izi pano; omwe akufuna azitha kuzifufuza okha.
Tiyeni tibwerere ku mafotokozedwe athu. Pambuyo pa kusintha kwathu, zidakhala momwe timafunira kuziwonera:
Kotero, tatsiriza kusiyanitsa koyamba. Tiyeni tipitirire ku mawu achiwiri.
Kusiyana 2
Tiyeni titsatire njira yopunthidwa. Idzakhala yayifupi kwambiri kuposa yapitayi, kotero musapite kutali kwambiri ndi chophimba.
Tiyeni tikulitse ma vectors ndi matrix element ndi chinthu:
Tiyeni tichotse awiriwa pa mawerengedwe kwa kanthawi - sizimasewera gawo lalikulu, ndiye tidzabwezeretsa m'malo mwake. Tiyeni tichulukitse ma vectors ndi matrix. Choyamba, tiyeni tichulukitse matrix ku vector , tilibe zoletsa pano. Timapeza kukula kwa vector :
Tiyeni tichite izi - chulukitsa vekitala ku vekitala yotuluka. Potuluka nambala ikhala ikutidikirira:
Ndiye tidzasiyanitsa. Pazotulutsa timapeza vector of dimension :
Mukundikumbutsa chinachake? Ndichoncho! Izi ndizopangidwa ndi matrix ku vector .
Motero, kusiyanitsa kwachiwiri kumatsirizidwa bwino.
M'malo mapeto
Tsopano tikudziwa momwe kufanana kunayambira .
Pomaliza, tifotokoza njira yachangu yosinthira mafomu oyambira.
Tiyeni tiwunikire mtundu wachitsanzo molingana ndi njira yocheperako:
Tiyeni tisiyanitse mawu otsatirawa:
Mabuku
Zochokera pa intaneti:
1)
2)
3)
4)
Mabuku, zosonkhanitsira zovuta:
1) Zolemba pamasamu apamwamba: maphunziro athunthu / D.T. Wolemba - 4th ed. - M.: Iris-press, 2006
2) Kugwiritsidwa ntchito kwa regression analysis / N. Draper, G. Smith - 2nd ed. - M.: Finance and Statistics, 1986 (kumasulira kuchokera ku Chingerezi)
3) Mavuto pakuthana ndi ma equation a matrix:
Source: www.habr.com