一.進(jìn)退法－－已經(jīng)調(diào)試好
程序名：II
功能：確定一維優(yōu)化問題搜索的初始區(qū)間
變量含義：
H0－－搜索區(qū)間步長(zhǎng)
X0－－初始點(diǎn)
有“!!!!”處語句為用戶應(yīng)該修改的部分

主程序
1 REM MAIN PROGRAM
2 PRINT "INPUT: X0,H0"
3 INPUT X0,H0
4 GOSUB 1000
6 PRINT "PRIMAL DATA"
8 PRINT "X0=";X0,"H0=";H0
10 PRINT "INITAL INTERNAL"
12 PRINT "A=";A,"B=",B
14 END

子程序：
1000 REM FILE NAME:SS
1002 REM DETERMINATION OF THE INITIAL INTERVAL
1004 H=H0
1006 X1=X0:X=X1:GOSUB 8000:Y1=FX
1008 X2=X1+H:X=X2:GOSUB 8000:Y2=FX
1010 IF Y2<Y1 GOTO 1020
1012 H=-H0:X3=X1:Y3=Y1
1014 X1=X2:Y1=Y2:X2=X3:Y2=Y3
1020 H=2*H
1022 X3=X2+H:X=X3:GOSUB 8000:Y3=FX
1024 IF Y2>=Y3 GOTO 1014
1026 IF H<0 GOTO 1030
1028 A=X1:B=X3:GOTO 1032
1030 A=X3:B=X1
1032 RETURN



8000 REM OBJECTIVE FUNCTION
8005 FX=3*X^3-8*X+9:REM !!!!!!
8010 RETURN