程序代码：

目标函数：
function f=litifun(x)
x =[14 23 0.6 29.33 12 13];
a=4.75*x(1)*x(2)*x(2)*x(3)*x(3);
b=85*x(1)*x(2)*x(3)*x(3);
c=85*x(1)*x(3)*x(3);
d=0.92*x(1)*x(6)*x(6);
e=x(1)*x(5)*x(5);
f=0.8*x(1)*x(2)*x(3)*x(6);
h=1.6*x(1)*x(3)*x(6);
k=x(4)*x(5)*(5);
w=x(4)*x(6)*x(6);
f=0.78539815*(a+b-c+d-e+f-h+k+w+28*x(5)*x(5)+32*x(6)*x(6));

约束条件：
function [c,ceq]=lifun(x)
c(1)=17-x(2);
c(2)=x(2)*x(3)-30;
c(3)=0.2-x(3);
c(4)=16-x(1)/x(3);
c(5)=x(1)/x(3)-35;
c(6)=10-x(5);
c(7)=x(5)-15;
c(8)=13-x(6);
c(9)=x(6)-20;
c(10)=x(1)+0.5*x(6)-x(4)+4;
c(11)=43854/(x(2)*x(3)*sqrt(x(1)))-855;
c(12)=7098/(x(1)*x(2)*x(3)^2*(0.169+0.006666*x(2)-0.0000854*x(2)^2))-261;
c(13)=7098/(x(1)*x(2)*x(3)^2*(0.169+0.00177*x(2)-0.0000394*x(2)^2))-213;
c(14)=0.01233*x(4)^3/(x(2)*x(3)*x(5)^4)-0.003*x(4);
c(15)=29050*x(4)*sqrt(1+0.29709*x(2)^2*x(3)^2/x(4)^2)/(x(2)*x(3)*x(5)^3)-55;
c(16)=29050*x(4)*sqrt(1+0.29709*x(2)^2*x(3)^2/x(4)^2)/(x(2)*x(3)*x(6)^3)-55;
ceq=[];

输入函数：
ObjectiveFunction = @litifun;
nvars = 6;    % Number of variables
x=[0.5 20 0.6 30 12 15];
lb=[5 17 0.3 3 10 13];
ub=[40 100 2 50 15 20];
[c,ceq]=lifun(x)
ConstraintFunction = @lifun;
options=gaoptimset( 'PopulationSize',200,'Generations',200, 'CrossoverFraction',0.7 ,'MigrationFraction',0.01,'PopInitRange',[0;120],'InitialPopulation',x,'Display','iter');
[x,fval]=ga(ObjectiveFunction,nvars,[],[],[],[],lb,ub,ConstraintFunction,options)
   
怎样修改才能使得怎样修改才能使得X1取（5 40）之间的正整数,X2取（17 100）之间的正整数，X3只在（0.3,0.35,0.4,0.5,0.6,0.8,0.9,1,1.25,1.5,1.75,2）这些数中取值，X4、X5、X6不限