wilcox_R: What the package does (short line)

bdanova2 <-
function(x1,x2=NULL,alpha=.05,power=.9,delta){
#
#  Do the second stage of the Bishop-Duewicz ANOVA
#
if(is.null(x2[1])){
stage1=bdanova1(x1,alpha=alpha,power=power,delta=delta)
return(list(N=stage1$N,d=stage1$d,crit=stage1$crit))
}
if(!is.null(x2[1])){
if(is.na(delta))stop("A value for delta was not specified")
if(!is.list(x1)){
if(!is.matrix(x1))stop("Data must be stored in a matrix or in list mode")
y<-x1
x1<-list()
for(j in 1:ncol(y))x1[[j]]<-y[,j]
}
if(is.na(delta))stop("A value for delta was not specified")
if(!is.list(x2)){
if(!is.matrix(x2))stop("Data must be stored in matrix or in list mode")
y<-x2
x2<-list()
for(j in 1:ncol(y))x2[[j]]<-y[,j]
}
if(length(x1)!=length(x2))stop("Length of x1 does not match the length of x2")
TT<-NA
U<-NA
J<-length(x1)
nvec<-NA
nvec2<-NA
svec<-NA
for(j in 1:length(x1)){
nvec[j]<-length(x1[[j]])
nvec2[j]<-length(x2[[j]])
svec[j]<-var(x1[[j]])
TT[j]<-sum(x1[[j]])
U[j]<-sum(x2[[j]])
}
temp<-bdanova1(x1,alpha=alpha,power=power,delta=delta)
need<-temp$N-nvec
#for(j in 1:length(x1))print(c(nvec2[j],need[j]))
for(j in 1:length(x1))if(nvec2[j]<need[j]){
print(paste("Warning: For Group", j))
print("The first stage analysis based on bdanova1 reports that a larger")
print(" sample is required than what was found in the argument x2")
}
b<-sqrt(nvec*((nvec+nvec2)*temp$d-svec)/(nvec2*svec))
b<-(b+1)/(nvec+nvec2)
xtil<-TT*(1-nvec2*b)/nvec+b*U
ftil<-sum((xtil-mean(xtil))^2)/temp$d
return(list(test.stat=ftil,crit=temp$crit))
}
}