关于正二等轴测图及其作图方法

Qimetric drawing and its plotting method

主要论述正二等轴测图的有关问题。其中对国家标准（ＧＢ４４５８．３－８４）中关于正二等轴测图的某些提法及作图方法提出不同意见。同时，给出一种新的正二等轴测图的作图方法，并论证了该方法不仅简便，且理论上绝对准确，在此基础上讨论了空间任意位置圆的正二测投影——椭圆的作图和计算方法。

Abstract This paper discusses mainly about prollems relate to dimetric drawing.Among which different opinions have been advanced against certain wordings and plotting methed relate to dimetric drawing in the NationaI Standard(GB4458.3一～84).At the same time,a new method has been given for the pfotting of dimetric dravving and demonstrated that this method is not only simple but also absolutely accu-rate in theory.On this basis discussed the dimetric projection of circles positioned arbitrarily in space-the plotting and cal-cufative methed for ellipses.