, . (2.1).
X0 , a0 , . , XkÎEn ak>0 k³0. ej=(0,,0,1,0,,0) , j- 1, , j=1,,n.
Sk=ejk, jk=k-n +1, (2.13)
- k/n. (2.13) e1,,en, .. S0=e1,, Sn-1=en, Sn=e1,,
S2n-1=en, S2n=e1.
f(X) X= Xk+ akSk
f(Xk+ akSk) < f(Xk). (2.14)
,
Xk+1= Xk+ akSk, ak+1=ak. (2.15)
, (2.14) , f(X) X= Xk -akSk
f(Xk - akSk) < f(Xk). (2.16)
(2.15)
Xk+1= Xk - akSk, ak+1=ak. (2.17)
(k+1) , (2.14) (2.16). , (k+1)
k+1=Xk, ak+1= (2.18)
lÎ(0;1) , . (2.18) , n e1,,en ak , ak n . n , ak .
. , .
, , x ix j, .. x i, i=1,,n.
, .
.
f(X) ej, j=1,,n . en , , , :
|f(Xk) - f(Xk-n)|<e || Xk - Xk-n||<e, (2.19)
e>0 - .
min{f(Xk - a×Sk) |aÎR} (2.20)
. .
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0. e>0, X0ÎEn, f(X0), k=0.
1. j=k-n +1, Sk=ej, k/n.
(2.20), .. ak=arg min{f(Xk+a×Sk)|aÎR}. Xk+1= Xk+akSk f(Xk+1).
2. j<n, k=k+1 1, 3.
3. (2.19). , 4, 1, k=k+1.
4. , X* Xk+1, f*f(Xk+1).
f(X). , , , , . .
-
(2.1) , Xk-Xk-n Xk, k=s×n, s . -.
- :
1) f(X);
2) .
X Dj, j=1,,n.
1. =X, j=1.
2. Y= - Djej, ej - j- . f(Y)³f(), 3, 4.
3. Y= +Djej. f(Y)³f(), 5, 4.
4. =Y.
5. j=j+1. j£n, 2. , .. , f()<f(X), ¹X.
, =X. . ||D||£e, e , X*=X. , Dj=Djg, gÎ(0;1) .
-.
0. X0ÎEn, D=(D1,, Dn), gÎ(0;1), e>0, k=0.
1. Xk k. k ¹Xk, 3, 2.
2. ||D||<e. , 5, Dj=Djg 1.
3. k k-Xk X= k+( k-Xk)=2 k-Xk.
4. X . f()<f( k), Xk= k, k =X 3. k=k+1, Xk=X 1.
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5. , X*=Xk, f *=f(Xk).
.
2.2.2 , f(X) .
X0ÎEn. (. 2.2.2), ..
Xn= X0+
ej , j 1, 0, j=1,,n. - a
a j =arg min {f(Xj-1+a ej) ½aÎR}.
f(X) : Sn+1=Xn-X0: Xn+1=Xn+an+1Sn+1, an+1 Sn+1 a:
a n+1 =arg min {f(Xn+aSn+1) | a>0}.
X0=Xn+1, . , (2.19).
1. f(X)=5x12+5x22+8x1x2 X0= (5;5) .
, - , 135 1. 3 .5. X , , f(X). , .
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.5.
( 1).
2. f(X)=(x1+1)2+x22 - X0=(2;3)T.
D=(2;3)T. f(X0)=18. , 4, X0
x1(1)=2+0,5=2,5; f(2,5;3)=21,25 ();
x1(1)=2-0,5=1,5; f(1,5;3)=15,25 ();
x2(1)=3+1=4; f(1,5;4)=22,25 ();
x2(1)=3-1=2; f(1,5;2)=10,25 ().
. X1=(1,5;2)T X1-X0 X2=2X1- X0:
x1(2)=2×1,5-2=1; x2(2)=2×2-3=1; f(1;1)=5.
X1=(1,5;2)T:
x1(3)=1+0,5=1,5; f(1,5;1)=7,25 > f(X2) ();
x1(3)=1-0,5=0,5; f(0,5;1)=3,25 < f(X2) ();
x2(3)=1+1=2; f(0,5;2)=6,25 > f(X2) ();
x2(3)=1-1=0; f(0,5;0)=2,25 < f(X2) ();
f(X3)=2,25< f(X1)=10,25 X1 X2=(1;1)T , X3
X4=2X3- X1:
x1(4)=2×0,5-1,5=-0,5; x2(4)=2×0-2=-2; f(-0,5;-2)=4,25.
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X4=(-0,5;-2)T:
x1(5)=-0,5+0,5=0; f(0;-2)=5 > f(X4) ();
x1(5)=-0,5-0,5=-1; f(-1;-2)=4 > f(X4) ();
x2(5)=-2+1=-1; f(-0,5;-1)=1,25 < f(X4) ().
f(X5)=1,25< f(X3)=2,25 X3 X4 , , f(X) , . . .6 . f(X)=(x1+1)2+x22 X*=(-1;0). , . .
.6. .7.
- ( 2). ( 3).
3. f(X)=2x12+x22-x1x2 X0=(2;2)T(.7).
f(X) , x1 67,5. (. 2.2.2) X0 -e1=(-1;0), .. f(X0 ae1) a>0 . X1=X0- a1e1, a1=arg min{f(X0 ae1)|a>0}. , f(X)=const. X1 -e2=(0;-1) X2=X1-a2e2, a2=arg min{f(X1 ae2)|a>0}. X2 X2- X0. f(X) , .