%function [m]=mengte(x)
n=100000; 
x1=normrnd(10,2,1,n);
x2=normrnd(2.5,0.375,1,n);
% % x3=normrnd(0.85,0.1105,1,n);  
%h=exp(normrnd(3.49,0.03,1,n))

%對數正態分布

% miu=
% sigma=
% delta=sigma/miu
% miu2=log(miu/sqrt(1+delta^2))
% sigma2=sqrt(log(1+delta^2))
% x3=normrnd(miu2,sigma2,1,n);

%--------------

% x1=lognrnd(2,0.4,1,n);
% x2=lognrnd(4,0.8,1,n);
%極值型分布
%r=rand(1，n)；R=Mu-0．45Mu’dlt-O．779 7 “。dh’log[-log(r)】
%q=70-20.3*0.45-0.7797*20.3*log(-log(rand(1,n)))


%功能函數
x3=0.1*x1;
x4=x2-1;

z=18.46-7.48*x3./(x4.^3);

%-----------

zz=find(z<0) 
k=length(zz) 
pf=k/n
fprintf('可靠度指標bata =%f\n', norminv(1-pf))

% %畫圖
% sort(r);
 %hist(r,100);