Help
isoline, i-isometric line — isiZulu
Umugqa odwetshwa kwibalazwe oxhumanisa amaphoyinti amabili anamanani alinganayo, ento ethile, endaweni ethile okwenziwa kuyona ucwaningo. Umbono oyisisekelo mayelana nalokhu wukuthi wonke amaphoyinti kulowo mugqa anenani elifanayo laleyonto ecwaningwayo. Ukuphakama kwendawo ethile kusuka olwandle kungasetshenziswa njengento ecwaningwayo okumele ichazwe. Ayikho ingxenye yomhlaba eyisicaba njengengxenye yetafula engaphezulu (table top); ngisho nezingxenye “eziyithafa kakhulu” emhlabeni (njengamathafa ase-Springbokvlakte emngceleni ophakathi kwesifundazwe sase-Gauteng kanye ne-Limpopo) ezibonakala ziyisicaba noma ziyithafa kakhulu, zinakho ukungalingani okuthile futhi izindawo ezithile ziphakeme kakhudlwana kusuka olwandle uma ziqhathaniswa nezinye, nakuba umehluko ungaba ngamasentimitha ambadlwana nje. Abacwaningi bomhlaba (land surveyors) basebenzisa amathuluzi okufuna nokuthola indawo ethile ukuthi ikuphi emhlabeni (okungamathuluzi anobuxhakaxhaka besimanjemanje obukwazi ukwenza imigilingwane eminingi kulezi zinsuku) ukukala ukuphakama kwendawo kusuka olwandle, emaphoyintini amaningana kuleyo ndawo ekalwayo. Ukuphakama kusuka olwandle kwezindawo ezithile eziphakeme ngokuphawulekayo futhi ezigqamile (ezibizwa ngama-spot heights uma ziboniswa ebalazweni) kanye nezindawo eziphansi kakhulu, kuyakalwa ngaso sonke isikhathi uma kucwaningwa indawo futhi abacwaningi bomhlaba bagcwalisa indawo ethile ngamaphoyinti akaliwe amaningi ngokudingekayo ukuze bakwazi ukwenza izilinganiso zabo zobude nesimo sendawo (triangulations) noma ukufezekisa ezinye izinjongo zabo (futhi uma ibhajethi ibavumela). Ngokususela ocwaningweni lwendawo abalwenzile, sebekhiqize ibalazwe elineqoqwana lamaphoyinti abawabonisile ebalazweni kanye nobungako bokuphakama kwawo kusuka olwandle, kodwa ayikho iphethini yesimo sendawo engabonakala kwibalazwe elinjalo futhi awukho umfanekiso ongenzeka onhlangothi-ntathu (three dimensional visualization) waleyo ndawo. Kepha-ke, izazi zejografi ziyawacwaninga ngaso sonke isikhathi amaphethini esimo sendawo futhi-ke kuyadingeka ukuthi zenze umfanekiso onhlangothi-ntathu wobuso bomhlaba. Ukwengeza ama-isometric lines kuleli balazwe elishiwo ngenhla elikhiqizwe ngabacwaningi bomhlaba, kwenza ukuthi leyo ndawo icwaningeke ngokwejografi. Uma into ecwaningwayo kuwukuphakama kwendawo kusuka olwandle, ama-isolines abizwa ngokuthi ngama-contour lines futhi ibalazwe libizwa nge-contour map; ama-ioshyets yimigqa exhumanisa amaphoyinti anezinga lemvula elilinganayo ebalazweni elibonisa imvula, futhi ama-isotherms yimigqa ebonisa izingakushisa elilinganayo kunoma iliphi ibalazwe lesimo sezulu, njalo njalo. Ama-contour maps ngamabalazwe okusebenza ayisisekelo angasetshenziselwa nanoma yiluphi ucwaningo lwejografi oluphathelene nezinto ezibonakele ngamehlo ngoba phela izazi zejografi zinamehlo anobungoti futhi akwaziyo “ukufunda” ngokushesha indawo ku-contour map ngokwesimo sayo esiwunhlangothi-ntathu. Kepha-ke, kuyinto ethanda ukuba nzima ukuguqula ibalazwe elinama-spot heights libe yi-contour map, okusho, ukuthola nokutomula idatha yomugqa (line data) kwidatha yephoyinti (point data). Lokhu kudinga ulwazi olunzulu lwenqubo ye-interpolation, okuyinto umuntu ayifunda emva kwesikhathi eside eyizama. Kepha, izazi zejografi ezinesipiliyoni lokhu zikwenza ngokushesha okumangalisayo; empeleni lokhu kugcina sekuyinto ejwayelekile futhi ezenzekelayo nje kwizazi zejografi. (Bheka i-“interpolation” kanye ne-“spatial interpolation”.)
