「先經後緯」與「先橫再縱」

On the Sequence of Coordinates

當於二維的空間以坐標表示位置時，是先寫縱坐標，繼以橫坐標，還是相反？以球面直角坐標表示時，是「先經後緯」抑或「先緯後經」？平面直角坐標需與球面直角坐標順序相同嗎？測量教學是否應配合數學教學？本文回顧當今國內現況，比對美、日、中國大陸使用方式，以期說明不同表示方式之背景。誠然，一致性對於有效溝通與持續發展之建構，有良好功效。但是，若各執一端，淪於「大頭族」與「小頭族」戰爭，當不是社會之福。就實務面而言，明確表達是避免誤解的重要關鍵。

While expressing the position of an object in a two dimensional space with coordinates, which coordinate should be placed first? For spherical coordinates, the longitude or latitude? For plane coordinates, the vertical or the horizontal axis? For a system containing both, should the spherical and plane coordinates follow the same convention? Should surveying follow the convention of mathematics? This note reviews the current conventions in Taiwan, compared with the conventions used in the United States of America, Japan and mainland China. The objective of this paper is to describe the backgrounds of different sequences. Certainly, having one unified and strictly implemented representation plan has advantages in avoiding confusion. But, repeating the war between big endian and little endian would not be wise. From a practical side, maintaining clear expression would be the most important issue no matter whether unified or not.