Como faço para criar manualmente um objeto dendrograma (ou "hclust")? (em R)

Question

Eu tenho um dendrograma dado a mim como imagens. Como não é muito grande, eu posso construí -lo "manualmente" em um objeto R.

Então, minha pergunta é como faço para criar manualmente um objeto dendrograma (ou "hclust") quando tudo o que tenho é a imagem do dendrograma?

Vejo que existe uma função chamada "AS.Dendrogram", mas não consegui encontrar um exemplo sobre como usá -lo.

(PS: este post está seguindo minha pergunta de aqui)

Muito obrigado tal

Answer 1

Eu acho que você é melhor de criar um hclust objeto e depois convertê -lo em um dendrograma usando as.dendrogram, tentando criar um dendrograma diretamente. Olhe para a ?hclust página de ajuda para ver o significado dos elementos de um hclust objeto.

Aqui está um exemplo simples com quatro folhas A, B, C e D, combinando o primeiro AB, depois CD e finalmente ab-CD:

a <- list()  # initialize empty object
# define merging pattern: 
#    negative numbers are leaves, 
#    positive are merged clusters (defined by row number in $merge)
a$merge <- matrix(c(-1, -2,
                    -3, -4,
                     1,  2), nc=2, byrow=TRUE ) 
a$height <- c(1, 1.5, 3)    # define merge heights
a$order <- 1:4              # order of leaves(trivial if hand-entered)
a$labels <- LETTERS[1:4]    # labels of leaves
class(a) <- "hclust"        # make it an hclust object
plot(a)                     # look at the result   

#convert to a dendrogram object if needed
ad <- as.dendrogram(a)

Answer 2

Completamente manual ... não recomendado para grandes conjuntos de dados.

tree<-list();
attributes(tree)<-list(members=18,height=3);
class(tree)<-"dendrogram";

tree[[1]]<-list();
attributes(tree[[1]])<-list(members=4,height=2,edgetext="1");
 tree[[1]][[1]]<-list();
 attributes(tree[[1]][[1]])<-list(members=2,height=1,edgetext="H");
  tree[[1]][[1]][[1]]<-list();
  attributes(tree[[1]][[1]][[1]])<-list(members=1,height=0,edgetext="H",label="1HH",leaf=TRUE);
  tree[[1]][[1]][[2]]<-list();
  attributes(tree[[1]][[1]][[2]])<-list(members=1,height=0,edgetext="T",label="1HT",leaf=TRUE);
 tree[[1]][[2]]<-list();
 attributes(tree[[1]][[2]])<-list(members=2,height=1,edgetext="T");
  tree[[1]][[2]][[1]]<-list();
  attributes(tree[[1]][[2]][[1]])<-list(members=1,height=0,edgetext="H",label="1TH",leaf=TRUE);
  tree[[1]][[2]][[2]]<-list();
  attributes(tree[[1]][[2]][[2]])<-list(members=1,height=0,edgetext="T",label="1TT",leaf=TRUE);
tree[[2]]<-list();
attributes(tree[[2]])<-list(members=2,height=2,edgetext="2");
 tree[[2]][[1]]<-list();
 attributes(tree[[2]][[1]])<-list(members=1,height=0,edgetext="H",label="2H",leaf=TRUE);
 tree[[2]][[2]]<-list();
 attributes(tree[[2]][[2]])<-list(members=1,height=0,edgetext="T",label="2T",leaf=TRUE);
tree[[3]]<-list();
attributes(tree[[3]])<-list(members=4,height=2,edgetext="3");
 tree[[3]][[1]]<-list();
 attributes(tree[[3]][[1]])<-list(members=2,height=1,edgetext="H");
  tree[[3]][[1]][[1]]<-list();
  attributes(tree[[3]][[1]][[1]])<-list(members=1,height=0,edgetext="H",label="3HH",leaf=TRUE);
  tree[[3]][[1]][[2]]<-list();
  attributes(tree[[3]][[1]][[2]])<-list(members=1,height=0,edgetext="T",label="3HT",leaf=TRUE);
 tree[[3]][[2]]<-list();
 attributes(tree[[3]][[2]])<-list(members=2,height=1,edgetext="T");
  tree[[3]][[2]][[1]]<-list();
  attributes(tree[[3]][[2]][[1]])<-list(members=1,height=0,edgetext="H",label="3TH",leaf=TRUE);
  tree[[3]][[2]][[2]]<-list();
  attributes(tree[[3]][[2]][[2]])<-list(members=1,height=0,edgetext="T",label="3TT",leaf=TRUE);
tree[[4]]<-list();
attributes(tree[[4]])<-list(members=2,height=2,edgetext="4");
 tree[[4]][[1]]<-list();
 attributes(tree[[4]][[1]])<-list(members=1,height=0,edgetext="H",label="4H",leaf=TRUE);
 tree[[4]][[2]]<-list();
 attributes(tree[[4]][[2]])<-list(members=1,height=0,edgetext="T",label="4T",leaf=TRUE);
tree[[5]]<-list();
attributes(tree[[5]])<-list(members=4,height=2,edgetext="5");
 tree[[5]][[1]]<-list();
 attributes(tree[[5]][[1]])<-list(members=2,height=1,edgetext="H");
  tree[[5]][[1]][[1]]<-list();
  attributes(tree[[5]][[1]][[1]])<-list(members=1,height=0,edgetext="H",label="5HH",leaf=TRUE);
  tree[[5]][[1]][[2]]<-list();
  attributes(tree[[5]][[1]][[2]])<-list(members=1,height=0,edgetext="T",label="5HT",leaf=TRUE);
 tree[[5]][[2]]<-list();
 attributes(tree[[5]][[2]])<-list(members=2,height=1,edgetext="T");
  tree[[5]][[2]][[1]]<-list();
  attributes(tree[[5]][[2]][[1]])<-list(members=1,height=0,edgetext="H",label="5TH",leaf=TRUE);
  tree[[5]][[2]][[2]]<-list();
  attributes(tree[[5]][[2]][[2]])<-list(members=1,height=0,edgetext="T",label="5TT",leaf=TRUE);
tree[[6]]<-list();
attributes(tree[[6]])<-list(members=2,height=2,edgetext="6");
 tree[[6]][[1]]<-list();
 attributes(tree[[6]][[1]])<-list(members=1,height=0,edgetext="H",label="6H",leaf=TRUE);
 tree[[6]][[2]]<-list();
 attributes(tree[[6]][[2]])<-list(members=1,height=0,edgetext="T",label="6T",leaf=TRUE);


windows(width=3,rescale="fixed");
par(ps=8);
plot(rev(tree),center=TRUE,horiz=TRUE);