getTransmissionTree {nosoi}

Gets the full transmission tree (phylogenetic tree-like) from a nosoi simulation

Description

From a nosoi simulated epidemics, this function extracts the full transmission tree in a form mimicking a phylogenetic tree.

Usage

getTransmissionTree(nosoiInf)

Arguments

nosoiInf

an object of class nosoiSim

Details

This function uses packages tidytree and treeio, that rely on ape.

Value

A tree of class treedata, containing a phylogenetic tree based on the transmission chain and the mapped data at all the nodes.

See Also

For exporting the annotated tree to other software packages, see functions in treeio (e.g. write.beast).

To sub-sample this tree, see functions sampleTransmissionTree and sampleTransmissionTreeFromExiting

Examples

t_incub_fct <- function(x){rnorm(x,mean = 5,sd=1)}
p_max_fct <- function(x){rbeta(x,shape1 = 5,shape2=2)}
p_Exit_fct  <- function(t){return(0.08)}
p_Move_fct  <- function(t){return(0.1)}

proba <- function(t,p_max,t_incub){
  if(t <= t_incub){p=0}
  if(t >= t_incub){p=p_max}
  return(p)
}

time_contact = function(t){round(rnorm(1, 3, 1), 0)}

transition.matrix = matrix(c(0, 0.2, 0.4, 0.5, 0, 0.6, 0.5, 0.8, 0),
                           nrow = 3, ncol = 3,
                           dimnames = list(c("A", "B", "C"), c("A", "B", "C")))

set.seed(805)
test.nosoi <- nosoiSim(type="single", popStructure="discrete",
                        length=20,
                        max.infected=100,
                        init.individuals=1,
                        init.structure="A",
                        structure.matrix=transition.matrix,
                        pMove=p_Move_fct,
                        param.pMove=NA,
                        nContact=time_contact,
                        param.nContact=NA,
                        pTrans = proba,
                        param.pTrans = list(p_max=p_max_fct,
                                            t_incub=t_incub_fct),
                        pExit=p_Exit_fct,
                        param.pExit=NA
)

## Make sure all needed packages are here
if (requireNamespace("ape", quietly = TRUE) &&
    requireNamespace("tidytree", quietly = TRUE) &&
    requireNamespace("treeio", quietly = TRUE)) {
  library(ape)
  library(tidytree)
  library(treeio)

  #' ## Full transmission tree
  ttreedata <- getTransmissionTree(test.nosoi)
  plot(ttreedata@phylo)

  ## Sampling "non dead" individuals
  hID <- c("H-1", "H-7", "H-15", "H-100")
  samples <- data.table(hosts = hID,
                        times = c(5.2, 9.3, 10.2, 16),
                        labels = paste0(hID, "-s"))

  sampledTree <- sampleTransmissionTree(test.nosoi, ttreedata, samples)
  plot(sampledTree@phylo)

  ## Sampling "dead" individuals
  sampledDeadTree <- sampleTransmissionTreeFromExiting(ttreedata, hID)
  plot(sampledDeadTree@phylo)
  }