刚刚接触matlab算法，想请问一下，关于无法列出系数矩阵的方程组，如何在matlab中实现高斯-赛德尔（Gauss-Seidel）迭代？
（因为方程组中有很多三角函数，所以无法摘出完整的系数矩阵）例如下面这个方程组？
之前尝试过换元法，但是未知数越多解的难度指数倍上涨，感觉不具备可行性。
感谢各位专业人士解答！
f1=(-sin(1*x1)+sin(1*x2)-sin(1*x3)+sin(1*x4)-sin(1*x5)+sin(1*x6))-pi/700;
f2=(cos(1*x1)-cos(1*x2)+cos(1*x3)-cos(1*x4)+cos(1*x5)-cos(1*x6))-pi/700;
f3=(-sin(3*x1)+sin(3*x2)-sin(3*x3)+sin(3*x4)-sin(3*x5)+sin(3*x6))-3*pi/700;
f4=(cos(3*x1)-cos(3*x2)+cos(3*x3)-cos(3*x4)+cos(3*x5)-cos(3*x6))-3*pi/700;
f5=(-sin(5*x1)+sin(5*x2)-sin(5*x3)+sin(5*x4)-sin(5*x5)+sin(5*x6))-5*pi/700;
f6=(cos(5*x1)-cos(5*x2)+cos(5*x3)-cos(5*x4)+cos(5*x5)-cos(5*x6))-5*pi/700;
