变成矩阵形式 n+b2x+b∑x+…+b∑X=∑ bX,tb)x' ∑XX+…+b∑XX=∑X X+bX+b∑XX+…+∑x=∑X ∑X,∑X ∑X X XX XX XY X XX ∑K ∑正规方程 变成矩阵形式         + + + + = + + + + = + + + + =               ki i ki ki i ki i ki k i i k ki i i i i i i i k ki i b X b X X b X X b X X Y b X b X b X X b X X X Y nb b X b X b X Y 2 0 1 1 2 2 2 2 1 1 1 2 1 0 1 1 0 1 1 2 2 ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ ˆ                   =                                             ki i i i i k ki ki i ki i ki i i ki i i i i i ki X Y X Y Y b b b b X X X X X X X X X X X X n X X X           1 2 1 0 2 1 2 2 1 1 2 1 1 1 2 ˆ ˆ ˆ ˆ