Wc.stat<-function(Y0,N0,Y1,N1,YC,NC,S2) {
 # Hoel-Yanagawa conditional two-sample test
 # Y0 (Y1) = number of successes in the concurrent control (treatment)
 #             groups
 # N0 (N1) = number of trials in the concurrent control (treatment)
 #             groups
 # YC (NC) = number of successes (trials) in the histor. control data
 #      S2 = variance in historical control proportions
 #
   mu.C <- YC/NC
   phi.C <- (S2 - mu.C*(1-mu.C)/NC) / (mu.C*(1-mu.C) - S2)
   a.C <- mu.C/phi.C
   b.C <- (1-mu.C)/phi.C
   N.plus <- N0 + N1
    temp <- N0 + a.C + b.C
    T.C <- (temp*Y1 - N1*(Y0 + a.C)) / (N1+temp)
    p.0 <- (Y0+a.C)/temp
    se.TC <- sqrt(temp/(temp+1)*p.0*(1-p.0)*(N1 - N1^2/(N1+temp)))
   W.C <- T.C/se.TC

   data.frame(ac=a.C,bc=b.C,muC=mu.C,phiC=phi.C,Tc=T.C,se.Tc=se.TC,
              Wc=W.C,pvalue=1-pnorm(W.C))
 }