最小二乘法是一种数学优化技术。它通过最小化误差的平方和寻找数据的最佳函数匹配。利用最小二乘法可以简便地求得未知的数据，并使得这些求得的数据与实际数据之间误差的平方和为最小。最小二乘法还可用于曲线拟合。其他一些优化问题也可通过最小化能量或最大化熵用最小二乘法来表达。-Least squares method is a mathematical optimization techniques. It matches by squaring and finding data to minimize the error of the best functions. Least square method can easily be obtained unknown data, and so these squared error between the obtained data and the actual data and the minimum. The least squares method can be used for curve fitting. Some other optimization problems can be expressed by the least squares method by minimizing or maximizing entropy energy.