求问:对下面的函数求极大似然估计时,要求pram[4],pram[5],pram[6]要大于0小于1
求问:对下面的函数求极大似然估计时,要求pram[4],pram[5],pram[6]要大于0小于1,它们的和要等于1,用哪个函数可以求得这个极大似然估计,麻烦大佬帮帮忙
logfun=function(pram){
y1=pram[1];y2=pram[2];y3=pram[3];y4=pram[4];y5=pram[5];y6=pram[6]
l=sum(log(y4*exp(-((-log(U1))^(1/y1)+(-log(U2))^(1/y1))^y1)*((log(U1)*log(U2))^(1/y1-1))
*(((-log(U1))^(1/y1)+(-log(U2))^(1/y1))^y1+1/y1-1)
/((U1*U2)*((((-log(U1))^(1/y1)+(-log(U2))^(1/y1))^y1)^(2-y1)))
+y5*(1+y2)*((U1*U2)^(-y2-1))*((U1^(-y2)+U2^(-y2)-1)^(-2-1/y2))
+y6*y3*(1-exp(-y3))*exp(-y3*(U1+U2))/(((1-exp(-y3))-(1-exp(-y3*U1))*(1-exp(-y3*U2)))^2)))
return(-l)
}