"sim.conn" <-
function(Eall,N,prop,rconn,beta)
  {
    nA <- as.integer(prop*N)
    nB <- N-nA

    denom <- beta*nA^2*rconn - beta*nA*rconn + beta*nA*nB + rconn*nA*nB - rconn*nB + nB^2
    pA <- rconn*beta*N*Eall/denom
    pB <- -N*Eall*(rconn-nA*rconn-nB+beta*nA)/(nB-1)/denom
    pAB <- beta*N*Eall/denom

    MBp <- new("MBparams")
    MBp <- addParams(x=MBp,N=N,m=2)
    MBp <- calcSim(x=MBp,func=sim.thresh,pNum=2)

    MBp@Sim[[1]] <- matrix(0,N,N)
    MBp@Sim[[1]][1:nA,1:nA][upper.tri(MBp@Sim[[1]][1:nA,1:nA])] <- rbinom(choose(nA,2),1,pA)
    MBp@Sim[[1]][1:nA,(nA+1):N] <- rbinom(nA*nB,1,pAB)
    MBp@Sim[[1]][(nA+1):N,(nA+1):N][upper.tri(MBp@Sim[[1]][(nA+1):N,(nA+1):N])] <- rbinom(choose(nB,2),1,pB)
    MBp@Sim[[1]] <- MBp@Sim[[1]]+t(MBp@Sim[[1]])
    MBp@Sim[[1]] <- as.matrix.csr(MBp@Sim[[1]])

    return(MBp)
  }