• The latitudinally equal-differential polyconic projection (等差分纬线多圆锥投影) is a polyconic map projection in use since 1963 in mainland China. Maps on this...
    2 KB (263 words) - 16:31, 4 August 2023
  • called the Finite difference method based on variation principles (基于变分原理的差分方法). This method was also independently invented in the West, and is more widely...
    6 KB (644 words) - 13:00, 8 February 2023