sdir2cas

代码说明：

  s平面中直接形式到级联形式的转换 ％适合模拟滤波器的 ％C为增益系数 ％B为包含各bk的K乘3维实系数矩阵 ％A为包含各ak的K乘3维实系数矩阵 ％b为直接形式的分子多项式系数 ％a为直接形式的分母多项式系数(s-plane in the direct form and cascade form of analog filters suitable for conversion of C for the gain coefficient B to include the bk of the K x 3-dimensional real coefficient matrix A to include all of K by ak real 3-dimensional coefficient matrix b for direct forms of molecular polynomial coefficients a direct form of the denominator polynomial coefficients)