R/leafsfirst.tail.R

In denpro: Visualization of Multivariate Functions, Sets, and Data

leafsfirst.tail<-function(dendat, rho=0, refe=NULL, dist.type="euclid")
{

n<-dim(dendat)[1]
d<-dim(dendat)[2]
pcfhigh<-dendat+rho
pcfdown<-dendat-rho
if (is.null(refe)){
      refe<-matrix(0,1,d)
      for (i in 1:d) refe[1,i]<-mean(dendat[,i])
      refe<-refe[1:d]
}

distat<-sqrt(pituus(dendat-t(matrix(refe,d,n))))
lkm<-n
infopointer<-seq(1,lkm)
if (length(rho)==1) rho<-rep(rho,lkm)

# order the atoms for the level set with level "lev"

ord<-order(distat)
infopointer<-infopointer[ord]

# create tree

parent<-matrix(0,lkm,1)
child<-matrix(0,lkm,1)
sibling<-matrix(0,lkm,1)
volume<-matrix(0,lkm,1)
radius<-matrix(0,lkm,1)

highestNext<-matrix(0,lkm,1)    #pointers to the nodes without parent
boundrec<-matrix(0,lkm,2*d) #for each node, the box which bounds all the c:dren

node<-lkm  #ord[lkm]  #the 1st child node is the one with the longest distance
parent[node]<-0
child[node]<-0
sibling[node]<-0

# radius
radius[node]<-distat[ord[node]]

volume[node]<-1

beg<-node                 #first without parent
highestNext[node]<-0
note<-infopointer[node]   #note<-pcf$nodefinder[infopointer[node]]
for (i in 1:d){
  boundrec[node,2*i-1]<-pcfdown[note,i]   
  boundrec[node,2*i]<-pcfhigh[note,i]  
}

j<-2
while (j<=lkm){
    node<-lkm-j+1   #ord[lkm-j+1]

    # lisaa "node" ensimmaiseksi listaan
    highestNext[node]<-beg  #beg on listan tamanhetkinen ensimmainen
    beg<-node           

    # add node-singleton to boundrec
    rec1<-matrix(0,2*d,1)  #luo sigleton
    note<-infopointer[node]  #note<-pcf$nodefinder[infopointer[node]]
    for (i in 1:d){
         rec1[2*i-1]<-pcfdown[note,i]  
         rec1[2*i]<-pcfhigh[note,i] 
    }
    boundrec[node,]<-rec1

    # radius
    radius[node]<-distat[ord[node]]

    volume[node]<-1

    curroot<-highestNext[beg]  #node on 1., listassa ainakin 2
    prevroot<-beg
    ekatouch<-0
    while (curroot>0){
        #rhocur<-rho[infopointer[node]]  
        istouch<-touchstep.tail(node,curroot,boundrec,child,sibling,
                                infopointer,pcfdown,pcfhigh,rho,dendat,
                                dist.type=dist.type)

        if (istouch==1){

           # paivita parent, child, sibling, volume 
           parent[curroot]<-node           
           if (ekatouch==0) ekatouch<-1 else ekatouch<-0 
           if (ekatouch==1){
              child[node]<-curroot
           }
           else{  # since ekatouch==0, prevroot>0
              sibling[lastsib]<-curroot
           }

           volume[node]<-volume[node]+volume[curroot]

           radius[node]<-min(distat[ord[node]],distat[ord[curroot]])

           # attach box of curroot
           rec1<-boundrec[node,]
           rec2<-boundrec[curroot,] 
           boundrec[node,]<-boundbox(rec1,rec2)
           # poista "curroot" listasta 
           highestNext[prevroot]<-highestNext[curroot]

        }     
        # if curroot was not removed, we update prevroot
        # else curroot was removed, we update lastsib
        if (istouch==0) prevroot<-curroot else lastsib<-curroot 
        curroot<-highestNext[curroot]
    }
    j<-j+1
}

root<-1 #ord[1]  #root is the barycenter

maxdis<-distat[ord[length(ord)]]
center<-t(dendat[infopointer,])

lf<-list(
parent=parent,volume=volume,center=center,level=radius,
root=root,
infopointer=infopointer,
refe=refe,maxdis=maxdis,
dendat=dendat)

return(lf)
}