[R] If loop

[Steven Yen]

Can someone help me with the if loop below? In the subroutine, I 
initialize all of (joint12,marg1,marg2,cond12,cond21) as FALSE, and call 
with only one of them being TRUE:

,...,joint12=FALSE,marg1=FALSE,marg2=FALSE,cond12=FALSE,cond21=FALSE,,,,

joint12 seems to always kick in, even though I call with, e.g., marg1 
being TRUE and everything else being FALSE. My attempts with if... else 
if were not useful. Please help. Thanks.

v1<-cprob(z1,x1,a,b,mu1,mu2,rho,j+1,k+1)
     v0<-cprob(z0,x0,a,b,mu1,mu2,rho,j+1,k+1)

    ...

     me1<-me0<-NULL
     if(joint12) {me1<-cbind(me1,v1$p12); me0<-cbind(me0,v0$p12)}
     if(marg1)   {me1<-cbind(me1,v1$p1); me0<-cbind(me0,v0$p1)}
     if(marg2)   {me1<-cbind(me1,v1$p2); me0<-cbind(me0,v0$p2)}
     if(cond12)  {me1<-cbind(me1,v1$pc12); me0<-cbind(me0,v0$pc12)}
     if(cond21)  {me1<-cbind(me1,v1$pc21); me0<-cbind(me0,v0$pc21)}
     ...

   labels<-NULL
   if(joint12) labels<-c(labels,lab.p12)
   if(marg1)   labels<-c(labels,lab.p1)
   if(marg2)   labels<-c(labels,lab.p2)
   if(cond12)  labels<-c(labels,lab.pc12)
   if(cond21)  labels<-c(labels,lab.pc21)