R/clusterHMMs.R

In ataudt/aneufinder: Analysis of Copy Number Variation in Single-Cell-Sequencing Data

#' Cluster objects
#'
#' Cluster a list of \code{\link{aneuHMM}} or \code{\link{aneuBiHMM}} objects by similarity in their CNV-state.
#'
#' @param hmms A list of \code{\link{aneuHMM}} or \code{\link{aneuBiHMM}} objects or a character vector of files that contains such objects.
#' @param cluster Either \code{TRUE} or \code{FALSE}, indicating whether the samples should be clustered by similarity in their CNV-state.
#' @param exclude.regions A \code{\link{GRanges-class}} with regions that will be excluded from the computation of the clustering. This can be useful to exclude regions with artifacts.
#' @return An list() with ordered ID indices and the hierarchical clustering.
#' @importFrom stats as.dist cov.wt hclust
#' @export
#' @examples
#'## Get results from a small-cell-lung-cancer
#'lung.folder <- system.file("extdata", "primary-lung", "hmms", package="AneuFinderData")
#'lung.files <- list.files(lung.folder, full.names=TRUE)
#'models <- loadFromFiles(lung.files)
#'\dontrun{
#'# Plot unclustered heatmap
#'heatmapGenomewide(models, cluster=FALSE)}
#'## Cluster and reorder the models
#'clust <- clusterHMMs(models)
#'models <- models[clust$IDorder]
#'\dontrun{
#'# Plot re-ordered heatmap
#'heatmapGenomewide(models, cluster=FALSE)}
#'
clusterHMMs <- function(hmms, cluster=TRUE, exclude.regions=NULL) {

	## Load the files
	hmms <- loadFromFiles(hmms, check.class=c("aneuHMM", "aneuBiHMM"))

	## Only use HMMs where column 'copy.number' exists
	ptm <- startTimedMessage("Checking column 'copy.number'  ...")
	hmms2use <- numeric()
	for (i1 in 1:length(hmms)) {
	  hmm <- hmms[[i1]]
		if (!is.null(hmm$bins$copy.number)) {
		  if (is.null(hmm$ID)) {
		    stop("Need ID to continue.")
		  }
		  hmms2use[hmm$ID] <- i1
		}
	}
	hmms <- hmms[hmms2use]
	stopTimedMessage(ptm)

	## Clustering based on bins
	hc <- NULL
	if (cluster) {
		ptm <- startTimedMessage("Making consensus template ...")
		if (!is.null(hmms[[1]]$bins$copy.number)) {
  		constates <- sapply(hmms, function(hmm) { hmm$bins$copy.number })
		} else if (!is.null(hmms[[1]]$bins$state)) {
		  constates <- sapply(hmms, function(hmm) { suppressWarnings( initializeStates(levels(hmm$bins$state))$multiplicity[as.character(hmm$bins$state)] ) })
		}
		constates[is.na(constates)] <- 0
		vars <- apply(constates, 1, var, na.rm=TRUE)
		stopTimedMessage(ptm)

		ptm <- startTimedMessage("Clustering ...")
    ## Exclude regions ##
    if (!is.null(exclude.regions)) {
        ind <- findOverlaps(hmms[[1]]$bins, exclude.regions)@from
    		constates <- constates[-ind,]
    }
		dist <- stats::dist(t(constates))
		hc <- stats::hclust(dist)
		stopTimedMessage(ptm)
		# Reorder samples
		hmms2use <- hmms2use[hc$order]
		
	}

	return(list(IDorder=hmms2use, hclust=hc))
}