logctablepost=function(theta,data)
{
theta1=theta[,1]
theta2=theta[,2]
s1=data[1]; f1=data[2]; s2=data[3]; f2=data[4]
logitp1=(theta1+theta2)/2
logitp2=(theta2-theta1)/2
term1=s1*logitp1-(s1+f1)*log(1+exp(logitp1))
term2=s2*logitp2-(s2+f2)*log(1+exp(logitp2))
return(term1+term2)
}