The sum of the squares of the deviation of all points from the best line is the least it can be.
各点与最佳线偏离的平方之和，是所能获得的最小值。
2
If there appears to be a linear relationship test results should be established by appropriate statistical methods (e. g. by calculation of a regression line by the method of leastsquares).
如果其呈现线性关系，测试结果应该通过适当的统计学方法(例如，以最小二乘方来计算回归线)来确立。
3
A compound digital filtering method and a line fitting method based on the leastsquares are presented, which are used in the measurement system of interface parameters of artillery.