% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/untangle.R
\name{all_couple_rotations_at_k}
\alias{all_couple_rotations_at_k}
\title{Rotate tree branches for k}
\usage{
all_couple_rotations_at_k(dend, k, dend_heights_per_k, ...)
}
\arguments{
\item{dend}{a dendrogram object}

\item{k}{integer scalar with the number of clusters the tree should be cut into.}

\item{dend_heights_per_k}{a named vector that resulted from running
\link{heights_per_k.dendrogram}. When running the function many times, 
supplying this object will help improve the running time if using the
\link{cutree.dendrogram} method..}

\item{...}{not used}
}
\value{
A list with dendrogram objects with all the possible rotations
for k clusters (beyond the k-1 clusters!).
}
\description{
Given a tree and a k number of clusters, the tree is rotated so that the
extra clusters added from k-1 to k clusters are flipped.

This is useful for finding good trees for a \link{tanglegram}.
}
\examples{

\dontrun{
dend1 <- USArrests[1:5,] \%>\% dist \%>\% hclust \%>\% as.dendrogram
dend2 <- all_couple_rotations_at_k(dend1, k=2)[[2]]
tanglegram(dend1,dend2)
entanglement(dend1,dend2, L = 2) # 0.5

dend2 <- all_couple_rotations_at_k(dend1, k=3)[[2]]
tanglegram(dend1,dend2)
entanglement(dend1,dend2, L = 2) # 0.4

dend2 <- all_couple_rotations_at_k(dend1, k=4)[[2]]
tanglegram(dend1,dend2)
entanglement(dend1,dend2, L = 2) # 0.05
}
}
\seealso{
\link{tanglegram}, \link{match_order_by_labels},
\link{entanglement}, \link{flip_leaves}.
}
