计算二维斜激波各个变量之间的关系，输入波前马赫数，sita,beta之中的任何两个，可以求出压力，密度，马赫数等波后量与波前量的比值-Relationship between the variables of the calculation of two-dimensional oblique shock, out of any two of the Mach number, sita, beta, the input wavefront, which can be determined pre