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ukudwetshwa kwephrofayili — isiZulu
Inqubo yokudweba nokubonisa ingxenye encane yomhlaba, uma ibhekwa ngasohlangothini (side view) olulodwa, ukuze kwenziwe umfanekiso obonisa kahle lezo zindawo eziphakeme kakhulu kanye nalezo eziphansi kakhulu. Lokhu kwenziwa ngendlela yasemandulo elula nje, futhi into edingekayo nje yi-contour map yendawo (bheka i-“isometric line” kanye ne-“topographical map”). Uma kudingeka iphrofayili yendawo ethile ephakeme kakhulu noma ephansi kakhulu, ebalazweni kudwetshwa umugqa ovundlayo onqamula phakathi kuleyo ndawo osuka ephoyintini elilodwa uya kwelinye (esingathi yiphoyinti A no-B), okungamaphoyinti anjengama-trigonometric beacons amabili, abekwe ngapha nangapha kwaleyonto eboniswayo, bese kubekwa unqenqema lweheheba lephepha kulowo mugqa. Noma kuphi lapho umugqa unqamula kwi-contour line, kubekwa uphawu ekugcineni konqenqema lweheheba lephepha, bese kuqoshwa phansi i-altitude (bheka i-“isometric line”) yalelo phoyinti lengxenye yomhlaba. Emva kwalokho-ke kumele kwakhiwe iqoqwana lama-axes kwiheheba lephepha, ngaphansi komugqa onezimpawu ezibekwe onqeqemeni lweheheba. I-horizontal axis (x axis) imele ubude bebanga kusuka kuphoyinti A kuya ku-B, ngokwesilinganiso sobude bebanga sebalazwe (isibonelo, 1:50 000). Isilinganiso se-vertical axis (y axis) sikhethwa ngumuntu odweba iphrofayili futhi – ngokubheka ukuphakama noma ubuphansi bendawo edwetshwayo – kungaba ngcono ukuthi kusetshenziswe amamilimitha amabili (2 mm) kulowo mdwebo owenziwayo ukubonisa ubude boqobo bendawo ethile obungamamilimitha angama-20 m. Iphoyinti A libekwa ku-y axis ngokwe-altitude yalo, bese kuthi wonke ama-contour-intersection points aboniswe ngezimpawu ezibekwe onqeqemeni lweheheba lephepha abekwe ngendlela yokuthi izimo zawo ku-x axis ziphambane nama-altitude azo ku-y axis. Bese emva kwalokho kujoyinwa wonke amaphoyinti adwetshiwe ngomugqa owodwa obonisa umfanekiso wokuphakama nobuphansi boqobo baleyo ngxenye yomhlaba eboniswayo. Isici okugxilwe kusona sizobonakala ngokucacile kulo mugqa wephrofayili. Le ndlela yokudweba isemqoka kakhulu ku-geomorphology naku-geology futhi ku-geology, amaphrofayili anjalo avamise ukubizwa ngama-“cross sections”.
