这个程序是用来研究二维粒子网格法的，涉及PIC二维程序基本内容-This procedure is used to study two-dimensional particle-grid method, the basic content of the program involves a two-dimensional PIC

涉及粒子网格法PIC方法的静电场一维程序，里面包含PIC基本方法。-PIC method involves particle grid method of one-dimensional electrostatic field, which contains the basic method PIC.