(2.4) b 0, b 1 S = S (b 0, b 1).
S / b 0 = - 2 yi b 0 b 1 xi),
S / b 1 = - 2 (yi b 0 b 1 xi).
( ), , , , b 0, b 1:
b 0 n + b 1 S xi = S yi,
b 0 S xi + b 1 S xi 2 = S xi yi, (2.5)
. . , (2.4).
(2.5). 0. (b 0, b 1); b 1 ( ):
, (2.6)
i 1 n. b 0 :
b 0 = , (2.7)
:
= (y 1++ yn)/ n, = (x 1++ xn)/ n.
2.3.1. . b 1 b 1 :
. (2.8)
ij,
S(xi )(yi ) = S xi yi S yi S xi + n = S xi yi n =
= S xi yi (S xi)(S yi)/ n.
:
Sx y = S(xi )(yi ), Sx x = S(xi )2, Sy y = S(yi )2.
b 1:
b 1 = Sx y / Sx x . (2.9)
= = b 0 + b 1 x (2.10)
= g (x) (2.2). :
= + b 1(x ). (2.11)
(2.10) b 0 (2.7).
(2.11) , , = , (, ).
, D (2.5) 0. ǒ, .
D = n S xi 2 (S xi)2.
(S xi)2 = (S 1× xi)2, (S xi)2 S 12 × S xi 2 = n S xi 2,
D ³ 0 (2.12)
. , n - 1 = (1,,1) x = (x 1,, xn), (2.12) , 1 x . , 1, 2, 0
1 × 1 + 2 × x = 0, (2.13)
(0,,0). 2 = 0, , ( , 1 0, 1 = 0). (2.13) , x = (,, ), . , : x 1 = = xn = . (2.5) , , -
|
|
b 0 n + b 1 n = S yi, (2.14)
.
2.3.2. . , , (2.5) , , 0 . , (2.6) ((2.8)) (2.7). , x. , (2.14).
IJ 3