The mathematical model of bending logs of curved elliptical cylinder is analysed with the elliptical-archimedes spiral envelope in cylindric coordinate.
本文采用柱坐标，以椭圆—阿基米德螺线包络组成解析曲线椭圆柱体的弯曲原木的数学模型。
2
A method of digitization of map information was mathematically conducted and a computer programme was developed, according to the coordinate systems in cylinder and cone map projections.