会计学9.1遗传算法9.1.1遗传算法及其在最优化问题(wèntí)中的应用遗传算法的基本(jīběn)思想简单遗传算法的一般(yībān)步骤遗传算法和传统(chuántǒng)优化算法比较9.1.2遗传算法在求解(qiújiě)最优化问题中的应用举例例：绘制目标(mùbiāo)函数曲线：>>ezplot('x*sin(10*pi*x)+2',[-1,2])测试(cèshì)不同的初值：>>f=inline('-x.*sin(10*pi*x)-2','x');v=[];>>forx0=[-1:0.8:1.5,1.5:0.1:2]x1=fmincon(f,x0,[],[],[],[],-1,2);v=[v;x0,x1,f(x1)];end>>vv=-1.0000-1.0000-2.0000-0.2000-0.6516-2.65080.60000.6516-2.65081.40001.4507-3.45031.50000.2540-2.25201.60001.6506-3.65031.70001.2508-3.25041.80001.8505-3.85031.90000.4522-2.45112.00002.0000-2.0000编写(biānxiě)函数：function[sol,y]=c10mga1(sol,options)x=sol(1);y=x.*sin(10*pi*x)+2;％调用gaopt()函数>>[a,b,c,d]=gaopt([-1,2],'c10mga1');a,ca=1.850547466068883.85027376676810c=1.0e+002*0.010000000000000.016449613855480.036243958181770.020000000000000.016524973539880.036474140281400.160000000000000.018504685969750.038502680839510.230000000000000.018505539610090.038502737282281.000000000000000.018505474660690.03850273766768比较：>>ff=optimset;ff.Display='iter';>>x0=1.8;x1=fmincon(f,x0,[],[],[],[],-1,2,'',ff);f(x1)ans=-3.85027376676808>>f(a(1))%遗传算法结果ans=-3.85027376676810>>ezplot(‘x*sin(10*pi*x)+2’,[-1,20])％改变(gǎibiàn)求解区间>>[a,b,c,d]=gaopt([-1,20],'c10mga1');a,ca=19.4500520663286321.45002604650601c=1.0e+002*0.010000000000000.172432643584560.188586495324800.020000000000000.192535526393040.211337594879180.250000000000000.194500215305720.214500170811770.270000000000000.194500249617560.214500189812190.290000000000000.194500554933680.214500259355311.000000000000000.194500520663290.21450026046506>>ezplot(‘x*sin(10*pi*x)+2’,[12,20])％放大(fàngdà)区间>>[a,b,c,d]=gaopt([12,20],'c10mga1');a,ca=19.8500510433438321.85002552164857c=1.0e+002*0.010000000000000.176479303046260.196106376435940.030000000000000.176480913373820.196163740746970.050000000000000.188418582561280.202288599115410.210000000000000.198500642509440.218500238128620.230000000000000.198500559062540.218500252899931.000000000000000.198500510433440.21850025