code visual basic array matrix order java kutta runge method elliptical partial differential equation

精简的雪粒运动，用龙格库塔法来描述运动，在确定网格后，用双线性插值来确定实时雪粒的状态-Snow Grains streamlined movement, Runge-Kutta method used to describe the movement, in determining the grid, with bilinear interpolation to determine the real-time status and snowflakes

四阶龙格库塔算法, 用于微分方程求解，用于工程计算-Fourth-order Runge-Kutta algorithm for solving differential equations