Code to assemble the admitance matrix in power flow calculations

已经封装好的程序，用于计算电网的节点导纳矩阵，有界面，输入所需数据就可以得到结果-Packaging has a good program, used to calculate the grid node admittance matrix, interface, enter the required data can get results

潮流计算的PQ算法，包括输入函数、因子表计算、节点导纳矩阵的形成等。-PQ flow calculation algorithm, including the input function, factor table calculation, the formation of the node admittance matrix and so on.