Indlela Yokufunda Nokuhumusha Amagrafu Ezibalo Ngokufanele
Amagrafu ezibalo avame ukusetshenziselwa ukwethula idatha ngendlela emfushane neqondakala kalula. Kusukela emibikweni yebhizinisi kanye nezindaba zezomnotho kuya ocwaningweni lwezemfundo kanye nokuthunyelwe ezinkundleni zokuxhumana, amagrafu asisiza sibone izitayela, ukuqhathanisa, kanye namaphethini okunzima ukuwaqonda kusukela ezinombolweni ezingavuthiwe zodwa. Kodwa-ke, amagrafu angadukisa futhi uma efundwa ngokushesha noma edalwe ngendlela engalungile. Ngakho-ke, kubalulekile ukwazi ukuthi ungawafunda kanjani futhi uwahumushe kanjani amagrafu ezibalo ngendlela efanele ukuze ugweme izinqumo neziphetho ezingalungile.
1. Qonda umongo kanye nenhloso yegrafu
Isinyathelo sokuqala ngaphambi kokubheka umugqa, ibha, noma umbala kugrafu ukuqonda umongo wawo. Zibuze: Imayelana nani le datha? Ubani oqoqe idatha? Igrafu yadalwa ngayiphi injongo? Amagrafu emibikweni kahulumeni, omagazini besayensi, noma ezikhangisweni zomkhiqizo angaba nemiyalezo ehlukene. Ukuqonda umongo kuzokusiza ukuthi uhlole ukuthi igrafu yadalelwa ukuchaza isimo esiqondile, ukusekela impikiswano ethile, noma ngisho nokuthonya umbono.
Ngaphezu kwalokho, cabangela isikhathi kanye nesifunda esihlanganisiwe. Ishadi lokukhuphuka kwentengo lezinyanga eziyi-12 ngokuqinisekile lizodala umbono ohlukile kuneshadi leminyaka engama-20. Ukushintsha isikali sesikhathi kungakhulisa noma kunciphise umbono wokushintshashintsha kwedatha.
2. Thola uhlobo lwegrafu nokuthi yikuphi ukufundwa okufanele kakhulu
Uhlobo ngalunye lweshadi lunomsebenzi oyinhloko:
– Ishadi lebha: lifanele ukuqhathanisa izigaba, isibonelo ukuthengiswa ngomkhiqizo ngamunye.
– Ishadi lomugqa: lilungele ukubuka izitayela ngokuhamba kwesikhathi, isibonelo amanani esitoko ansuku zonke.
– Ishadi lephayi: libonisa isilinganiso sezingxenye kuyo yonke into, isibonelo isabelo semakethe, kodwa alisebenzi kahle uma kunezigaba eziningi noma zingahlukile kakhulu.
– I-Histogram: ibonisa ukusatshalaliswa kwedatha yezinombolo, isibonelo ukusatshalaliswa kwamaphuzu ezivivinyo.
– Isakhiwo se-Scatter (umdwebo we-scatter): sibona ubudlelwano phakathi kweziguquguquko ezimbili, isibonelo amahora okufunda kanye namamaki.
Ukwazi uhlobo lweshadi kukusiza ukuthi ugxile kulwazi ofuna ngempela ukulugqamisa. Iphutha elivamile ukufunda ishadi lephayi ukuze uqhathanise umehluko omncane phakathi kwezigaba—lapho iso lomuntu linenkinga yokuhlukanisa indawo yesilayi kunobude bebha.
3. Funda isihloko, ilebula, amayunithi, kanye nenganekwane ngokucophelela.
Ukuchazwa okungalungile kuvame ukwenzeka hhayi ngoba igrafu iyinkimbinkimbi, kodwa ngoba umfundi uphuthelwa yisici esiyisisekelo:
– Isihloko sichaza umyalezo oyinhloko womfanekiso.
– Amalebula e-X kanye ne-Y axis abonisa ukuthi yiziphi iziguquguquko eziboniswayo.
– Amayunithi (iphesenti, i-rupiah, abantu abayinkulungwane, amatoni, inkomba) anquma incazelo yezinombolo.
– Inganekwane ichaza incazelo yemibala/imigqa ehlukene.
Isibonelo, igrafu efundeka nge-Y-axis ethi "Imali engenayo (izigidi zama-rupiah)" izoba nencazelo ehlukile kunethi "Imali engenayo (izigidi zama-rupiah)." Ngokufanayo, isikali esithi "ngabantu abayi-100.000" sihlukile "kunani eliphelele." Ukuqonda lezi zinto kuvimbela iziphetho ezingalungile kusukela ekuqaleni.
4. Hlola isikali kanye nesisekelo esingu-zero
Isikali se-Y-axis singenye yemithombo emikhulu yokukhetha. Uma i-Y-axis ingaqali ku-zero, umehluko omncane ungabonakala umangalisa. Isibonelo, ukwenyuka kusuka ku-98 kuya ku-100 kubukeka njengokugxuma okukhulu uma ishadi linciphisa isikali futhi libonisa kuphela ububanzi obungu-95–101.
Ukunquma ama-axes akukubi ngaso sonke isikhathi—ngezinye izikhathi kuyadingeka ukubona umehluko omncane—kodwa abafundi kufanele baqaphele umphumela obonakalayo. Zijwayeze ukubheka izinombolo zebanga lesikali bese ubuza: "Kushintsha malini ngempela uma kuqhathaniswa nesilinganiso esigcwele?"
5. Hlukanisa phakathi kwezinguquko eziphelele nezihlobene
Amashadi noma izindaba eziningi zisho “ukwenyuka okungu-50%” ngaphandle kokukhuluma ngesibalo sokuqala. Izinguquko ezihlobene (iphesenti) zivame ukuzwakala zinkulu, kodwa izinguquko eziphelele zingase zibe zincane.
Isibonelo, ukwenyuka kwenani lamacala kusuka ku-2 kuya ku-3 kumele ukwanda okungu-50%, kodwa ngokwemigomo ephelele, kumele ukwanda okungu-1 kuphela. Ngokuphambene nalokho, ukwenyuka kusuka ku-1.000 kuya ku-1.200 kumele ukwanda okungu-20% kodwa ukwenyuka okungu-200. Uma uhumusha igrafu, bheka kokubili—ukuthi inombolo yangempela ihluke kangakanani nokuthi iphesenti lishintsha kanjani—ukuze uqonde umthelela wangempela.
6. Qaphela ukuthi idatha ijwayelekile noma isebenzisa isilinganiso.
Amagrafu angabonisa idatha ngokuthi “ngomuntu ngamunye,” “ngomndeni ngamunye,” “ngabantu abayi-1.000,” noma “isilinganiso.” Lolu hlobo lokulungisa luwusizo ekuqhathaniseni okunobulungiswa, kodwa lungaphambukisa umbono.
Isibonelo, idolobha A lingase libe nezinga lobugebengu eliphakeme kunedolobha B ngoba inani labantu balo likhulu. Kodwa-ke, kubantu abayi-100.000 abahlala kulo, idolobha B lingase libe sengozini enkulu. Ngokufanayo, inani "lomholo ojwayelekile" lingabandlululwa uma kunabantu abambalwa abanemiholo ephezulu kakhulu; ezimweni ezinjalo, i-median ivame ukumelela kakhulu. Uma igrafu ibonisa isilinganiso kuphela, hlola ukuze ubone ukuthi kukhona yini ulwazi olwengeziwe njenge-median, range, noma ama-quartiles.
7. Qaphela ukuthi ukuhlobana kuphambaniswe nembangela.
Ama-scatter plot avame ukusetshenziswa ukukhombisa ubudlelwano phakathi kweziguquguquko ezimbili. Uma amachashazi akha iphethini, singasho ukuthi kukhona ubudlelwano. Kodwa-ke, ubudlelwano abusho njalo ukuthi kukhona imbangela.
Isibonelo, ukuthengiswa kwe-ayisikhilimu kuyanda ngesikhathi esifanayo namacala okuphelelwa amanzi emzimbeni. Lokhu akusho ukuthi i-ayisikhilimu ibangela ukuphelelwa amanzi emzimbeni; isici sesithathu (isimo sezulu esishisayo) sithonya kokubili. Uma ubheka igrafu yobudlelwano phakathi kwezinto eziguquguqukayo, zibuze: ingabe zikhona ezinye izinto ezingaba yimbangela? Ingabe umklamo wocwaningo uyasisekela isiphetho esiyimbangela, noma umane usikisela ukuhlangana?
8. Hlola usayizi wesampula kanye nomthombo wedatha
Igrafu ebonakala ikholisayo ayiveli kudatha eqinile. Osayizi abancane besampula bangadala ukuguquguquka okubonakala kukhulu, futhi idatha evela emithonjeni engathembekile ingadukisa.
Uma kungenzeka, thola: bangaki abaphendulile noma okubonwe? Indlela yokwenza amasampula ibinjani? Ingabe idatha isanda kwenzeka? Igrafu evela kucwaningo lwabantu abayi-100 ngokwemvelo izoba nokungaqiniseki okukhulu kunocwaningo lwabaphenduli abangamashumi ezinkulungwane. Amagrafu esayensi ngezinye izikhathi abonisa “imigoqo yamaphutha” noma izikhawu zokuzethemba ezibonisa ukungaqiniseki—lokhu kubalulekile ukukufunda, hhayi ukukushalazela.
9. Yazi amasu okubona angakhohlisa
Amasu amaningana okuklama angathonya ukuqonda:
– Ukusebenzisa i-3D kumashadi ebha/ipayi kungenza kube nzima ukuqhathanisa izilinganiso.
– Imibala ehluke kakhulu ingagqamisa izigaba ezithile.
– Ukuhleleka kwezigaba kungaqondisa ukuhumusha (isib. ukubeka amanani aqatha ekuqaleni/ekugcineni).
– Ukukhetha isikhathi esikhethiwe kungafihla izitayela zesikhathi eside.
Njengomfundi, yenza umkhuba wokuhlola amagrafu: ingabe iziphetho ziyashintsha uma isikali sandiswa, isikhathi sinwetshwa, noma izigaba zihlelwe kabusha?
10. Finyelela iziphetho ngokulinganayo bese usho imikhawulo.
Ngemva kokufunda igrafu, fingqa ngomusho obonisa amandla edatha. Uma igrafu ikhombisa ukuthambekela okukhuphukayo, isimo "sivame ukwanda phakathi nalesi sikhathi" esikhundleni sokuthi "sizoqhubeka nokukhula nakanjani." Uma idatha ihlanganisa isifunda esithile kuphela, ungahlanganisi bonke abantu.
Isiphetho esihle sivame ukuphendula izinto ezintathu: (1) iyini iphethini eyinhloko, (2) ukuthi ushintsho lukhulu kangakanani, kanye (3) yimiphi imikhawulo yokuchazwa.
I-Penutup
Ukufunda nokuhumusha amagrafu ezibalo ngendlela efanele kuyikhono elibalulekile enkathini yokugcwala kolwazi. Ngokuqonda umongo, ukuqaphela izinhlobo zamagrafu, ukuhlola amalebula nezikali, ukuhlukanisa izinguquko eziphelele nezihlobene, kanye nokugxeka imithombo yedatha kanye nokubandlulula okungaba khona okubonakalayo, uzobe uhlomele kangcono ukwenza izinqumo eziqhutshwa idatha. Amagrafu amahle kufanele asisize sibone iqiniso ngokucacile, hhayi nje ukuqinisa izinkolelo-mbono. Ngakho-ke, yiba umfundi wegrafu oqaphile: ungabheki nje izimo, kodwa uqonde incazelo yazo.
