1.看看Arithmetic Operators帮助文献
...If A is an m-by-n matrix with m ~= n and B is a column vector with m components, or a matrix with several such columns, then X = A\B is the solution in the least squares sense to the under- or overdetermined system of equations AX = B. ...
2.polyfit是一样的! cc就是一次项与常数项的系数