多维函数

大小的小

函数如下：y=(0.0206*x(2)^2/(2*9.81*x(1))+(0.5*(1-(x(2)/(4*x(3)*9.81*(x(4)-1040)/(3*0.43*1040))^0.5*(1-(x(3)/x(1))^2)*2.7183^(-(2.65*x(5)-3.32*x(5)^2.2))))+((0.25*(x(2)/(4*x(3)*9.81*(x(4)-1040)/(3*0.43*1040))^0.5*(1-(x(3)/x(1))^2)*2.7183^(-(2.65*x(5)-3.32*x(5)^2.2)))-1)^2+x(5)*x(2)/(4*x(3)*9.81*(x(4)-1040)/(3*0.43*1040))^0.5*(1-(x(3)/x(1))^2)*2.7183^(-(2.65*x(5)-3.32*x(5)^2.2)))^0.5)*(x(4)/1040-1)+1.8413*(x(2)/(9.81*x(1)))^2.7736*(0.5*(1-(x(2)/(4*x(3)*9.81*(x(4)-1040)/(3*0.43*1040))^0.5*(1-(x(3)/x(1))^2)*2.7183^(-(2.65*x(5)-3.32*x(5)^2.2))))+((0.25*(x(2)/(4*x(3)*9.81*(x(4)-1040)/(3*0.43*1040))^0.5*(1-(x(3)/x(1))^2)*2.7183^(-(2.65*x(5)-3.32*x(5)^2.2)))-1)^2+x(5)*x(2)/(4*x(3)*9.81*(x(4)-1040)/(3*0.43*1040))^0.5*(1-(x(3)/x(1))^2)*2.7183^(-(2.65*x(5)-3.32*x(5)^2.2)))^0.5)*0.43*x(3)/x(1)*(x(4)/1040-1))/(x(4)*x(5)/1040);

+ U  v  X5 y3 s/ S函数中有五个自变量，自变量之间没有任何的约束关系，但是自变量有范围，x(1)=[0.2,0.4],x(2)=[1.234,3],x(3)=[0.01,0.04],x(4)=[1190,1398],x(5)=[0.15,0.4], 劳烦大神指点看怎么编程，能求出自变量范围内的结果 ，谢谢

大小的小

fitnessFunction=@minf_5;nvars=5;
2 K5 {5 Y, q  ]  T0 N: R' [5 Yoptions=gaoptimset;
options=gaoptimset(options,'PopInitRange',[0;1]);
4 h  l9 F% H8 L  coptions = gaoptimset(options,'PopulationSize',100);
options=gaoptimset(options,'CrossoverFraction',0.9);
4 K+ e' g% G, E& _7 @8 Voptions=gaoptimset(options,'Generations',1000);
  Z% A2 D: O2 N, ^  k3 m: Yoptions=gaoptimset(options,'CrossoverFcn',{@crossoverheuristic,0.9});
9 k' P7 f& ~% J8 _4 y0 Y0 u3 l' moptions=gaoptimset(options,'MutationFcn',{@mutationuniform,0.02});
[x fval reason output population scores]=ga(@minf_5,nvars,options)
2 k$ v+ P% A+ l) H# jOptimization terminated: average change in the fitness value less than options.TolFun.
% w+ H0 m. U$ a" N  A
x =

    0.6026    0.0979    0.2421    0.9712    0.9449


8 H; B% j9 }( @! S% }+ f' r% xfval =

1 |2 w0 R6 G1 Y+ J  -1.6983e+03 - 1.4575e+01i
3 @* i7 X, L/ y2 k8 k+ K
附上我自己的遗传算法编程，首先是第三行的自变量范围，只能定义一个区间，不知道怎么分开定义五个自变量的范围，再就是这样计算结果竟然是个复数，还都是负号，跟我想要的正实数实在是相去甚远，

llbnmo

帮你顶一下

zaiyiaaaa

理论上最小值就是-2.83599462789046，如果非要为正，那就是0了。

大小的小

zaiyiaaaa 发表于 2020-7-9 10:50
理论上最小值就是-2.83599462789046，如果非要为正，那就是0了。

好吧，我再看看
! b! w# L8 v: b8 C, c+ V6 B