#'Posterior estimation for Dirichlet process mixture of multivariate (potentially skew) distributions models
#'
#'Partially collapse slice Gibbs sampling for Dirichlet process mixture of multivariate
#'normal, skew normal or skew t distributions.
#'
#'@details This function is a wrapper around the following functions:
#'\code{\link{DPMGibbsN}}, \code{\link{DPMGibbsN_parallel}},
#'\code{\link{DPMGibbsN_SeqPrior}}, \code{\link{DPMGibbsSkewN}}, \code{\link{DPMGibbsSkewN_parallel}},
#'\code{\link{DPMGibbsSkewT}}, \code{\link{DPMGibbsSkewT_parallel}},
#'\code{\link{DPMGibbsSkewT_SeqPrior}}, \code{\link{DPMGibbsSkewT_SeqPrior_parallel}}.
#'
#'@seealso \code{\link{summary.DPMMclust}}
#'
#'@param data data matrix \code{d x n} with \code{d} dimensions in rows
#'and \code{n} observations in columns.
#'
#'@param hyperG0 prior mixing distribution.
#'
#'@param a shape hyperparameter of the Gamma prior
#'on the concentration parameter of the Dirichlet Process. Default is \code{0.0001}.
#'
#'@param b scale hyperparameter of the Gamma prior
#'on the concentration parameter of the Dirichlet Process. Default is \code{0.0001}. If \code{0},
#'then the concentration is fixed set to \code{a}.
#'
#'@param N number of MCMC iterations.
#'
#'@param doPlot logical flag indicating whether to plot MCMC iteration or not.
#'Default to \code{TRUE}.
#'
#'@param nbclust_init number of clusters at initialization.
#'Default to 30 (or less if there are less than 30 observations).
#'
#'@param plotevery an integer indicating the interval between plotted iterations when \code{doPlot}
#' is \code{TRUE}.
#'
#'@param diagVar logical flag indicating whether the variance of each cluster is
#'estimated as a diagonal matrix, or as a full matrix.
#'Default is \code{TRUE} (diagonal variance).
#'
#'@param verbose logical flag indicating whether partition info is
#'written in the console at each MCMC iteration.
#'
#'@param distrib the distribution used for the clustering. Current possibilities are
#'\code{"gaussian"}, \code{"skewnorm"} and \code{"skewt"}.
#'
#'@param ncores number of cores to use.
#'
#'@param type_connec The type of connection between the processors. Supported
#'cluster types are \code{"SOCK"}, \code{"FORK"}, \code{"MPI"}, and
#'\code{"NWS"}. See also \code{\link[parallel:makeCluster]{makeCluster}}.
#'
#'@param informPrior an optional informative prior such as the approximation computed
#'by \code{summary.DPMMclust}.
#'
#'@param ... additional arguments to be passed to \code{\link{plot_DPM}}.
#'Only used if \code{doPlot} is \code{TRUE}.
#'
#'@return a object of class \code{DPMclust} with the following attributes:
#' \item{\code{mcmc_partitions}:}{ a list of length \code{N}. Each
#' element \code{mcmc_partitions[n]} is a vector of length
#' \code{n} giving the partition of the \code{n} observations.}
#' \item{\code{alpha}:}{ a vector of length \code{N}. \code{cost[j]} is the cost
#' associated to partition \code{c[[j]]}}
#' \item{\code{U_SS_list}:}{ a list of length \code{N} containing the lists of
#' sufficient statistics for all the mixture components at each MCMC iteration}
#' \item{\code{weights_list}:}{ a list of length \code{N} containing the weights of each
#' mixture component for each MCMC iterations}
#' \item{\code{logposterior_list}:}{ a list of length \code{N} containing the logposterior values
#' at each MCMC iterations}
#' \item{\code{data}:}{ the data matrix \code{d x n} with \code{d} dimensions in rows
#'and \code{n} observations in columns}
#' \item{\code{nb_mcmcit}:}{ the number of MCMC iterations}
#' \item{\code{clust_distrib}:}{ the parametric distribution of the mixture component}
#' \item{\code{hyperG0}:}{ the prior on the cluster location}
#'
#'@author Boris Hejblum
#'
#'@references Hejblum BP, Alkhassim C, Gottardo R, Caron F and Thiebaut R (2019)
#'Sequential Dirichlet Process Mixtures of Multivariate Skew t-distributions for
#'Model-based Clustering of Flow Cytometry Data. The Annals of Applied Statistics,
#'13(1): 638-660. <doi: 10.1214/18-AOAS1209> <arXiv: 1702.04407>
#'\url{https://arxiv.org/abs/1702.04407} \doi{10.1214/18-AOAS1209}
#'
#'@export
#'
#'@examples
#'#rm(list=ls())
#'set.seed(123)
#'
#'# Exemple in 2 dimensions with skew-t distributions
#'
#' # Generate data:
#' n <- 2000 # number of data points
#' d <- 2 # dimensions
#' ncl <- 4 # number of true clusters
#' sdev <- array(dim=c(d,d,ncl))
#' xi <- matrix(nrow=d, ncol=ncl, c(-1.5, 1.5, 1.5, 1.5, 2, -2.5, -2.5, -3))
#' psi <- matrix(nrow=d, ncol=4, c(0.3, -0.7, -0.8, 0, 0.3, -0.7, 0.2, 0.9))
#' nu <- c(100,25,8,5)
#' proba <- c(0.15, 0.05, 0.5, 0.3) # cluster frequencies
#' sdev[, ,1] <- matrix(nrow=d, ncol=d, c(0.3, 0, 0, 0.3))
#' sdev[, ,2] <- matrix(nrow=d, ncol=d, c(0.1, 0, 0, 0.3))
#' sdev[, ,3] <- matrix(nrow=d, ncol=d, c(0.3, 0, 0, 0.2))
#' sdev[, ,4] <- .3*diag(2)
#' c <- rep(0,n)
#' w <- rep(1,n)
#' z <- matrix(0, nrow=d, ncol=n)
#' for(k in 1:n){
#' c[k] = which(rmultinom(n=1, size=1, prob=proba)!=0)
#' w[k] <- rgamma(1, shape=nu[c[k]]/2, rate=nu[c[k]]/2)
#' z[,k] <- xi[, c[k]] + psi[, c[k]]*rtruncnorm(n=1, a=0, b=Inf, mean=0, sd=1/sqrt(w[k])) +
#' (sdev[, , c[k]]/sqrt(w[k]))%*%matrix(rnorm(d, mean = 0, sd = 1), nrow=d, ncol=1)
#' }
#'
#' # Define hyperprior
#' hyperG0 <- list()
#' hyperG0[["b_xi"]] <- rowMeans(z)
#' hyperG0[["b_psi"]] <- rep(0,d)
#' hyperG0[["kappa"]] <- 0.001
#' hyperG0[["D_xi"]] <- 100
#' hyperG0[["D_psi"]] <- 100
#' hyperG0[["nu"]] <- d+1
#' hyperG0[["lambda"]] <- diag(apply(z,MARGIN=1, FUN=var))/3
#'
#'
#'if(interactive()){
#' # Plot data
#' cytoScatter(z)
#'
#' # Estimate posterior
#' MCMCsample_st <- DPMpost(data=z, hyperG0=hyperG0, N=2000,
#' distrib="skewt",
#' gg.add=list(ggplot2::theme_bw(),
#' ggplot2::guides(shape=ggplot2::guide_legend(override.aes = list(fill="grey45"))))
#' )
#' s <- summary(MCMCsample_st, burnin = 1600, thin=5, lossFn = "Binder")
#' s
#' plot(s)
#' #plot(s, hm=TRUE) # this can take a few sec...
#'
#'
#' # more data plotting:
#' library(ggplot2)
#' p <- (ggplot(data.frame("X"=z[1,], "Y"=z[2,]), aes(x=X, y=Y))
#' + geom_point()
#' + ggtitle("Unsupervised data")
#' + xlab("D1")
#' + ylab("D2")
#' + theme_bw()
#' )
#' p
#'
#' c2plot <- factor(c)
#' levels(c2plot) <- c("4", "1", "3", "2")
#' pp <- (ggplot(data.frame("X"=z[1,], "Y"=z[2,], "Cluster"=as.character(c2plot)))
#' + geom_point(aes(x=X, y=Y, colour=Cluster, fill=Cluster))
#' + ggtitle("True clusters")
#' + xlab("D1")
#' + ylab("D2")
#' + theme_bw()
#' + scale_colour_discrete(guide=guide_legend(override.aes = list(size = 6, shape=22)))
#' )
#' pp
#'}
#'
#'
#'
#'
#'# Exemple in 2 dimensions with Gaussian distributions
#'
#' set.seed(1234)
#'
#' # Generate data
#' n <- 2000 # number of data points
#' d <- 2 # dimensions
#' ncl <- 4 # number of true clusters
#' m <- matrix(nrow=2, ncol=4, c(-1, 1, 1.5, 2, 2, -2, -1.5, -2)) # cluster means
#' sdev <- array(dim=c(2, 2, 4)) # cluster standard-deviations
#' sdev[, ,1] <- matrix(nrow=2, ncol=2, c(0.3, 0, 0, 0.3))
#' sdev[, ,2] <- matrix(nrow=2, ncol=2, c(0.1, 0, 0, 0.3))
#' sdev[, ,3] <- matrix(nrow=2, ncol=2, c(0.3, 0.15, 0.15, 0.3))
#' sdev[, ,4] <- .3*diag(2)
#' proba <- c(0.15, 0.05, 0.5, 0.3) # cluster frequencies
#' c <- rep(0,n)
#' z <- matrix(0, nrow=2, ncol=n)
#' for(k in 1:n){
#' c[k] = which(rmultinom(n=1, size=1, prob=proba)!=0)
#' z[,k] <- m[, c[k]] + sdev[, , c[k]]%*%matrix(rnorm(2, mean = 0, sd = 1), nrow=2, ncol=1)
#' }
#'
#' # Define hyperprior
#' hyperG0 <- list()
#' hyperG0[["mu"]] <- rep(0,d)
#' hyperG0[["kappa"]] <- 0.001
#' hyperG0[["nu"]] <- d+2
#' hyperG0[["lambda"]] <- diag(d)
#'
#'
#'if(interactive()){
#' # Plot data
#' cytoScatter(z)
#'
#' # Estimate posterior
#' MCMCsample_n <- DPMpost(data=z, hyperG0=hyperG0, N=2000,
#' distrib="gaussian", diagVar=FALSE,
#' gg.add=list(ggplot2::theme_bw(),
#' ggplot2::guides(shape=ggplot2::guide_legend(override.aes = list(fill="grey45"))))
#' )
#' s <- summary(MCMCsample_n, burnin = 1500, thin=5, lossFn = "Binder")
#' s
#' plot(s)
#' #plot(s, hm=TRUE) # this can take a few sec...
#'
#'
#' # more data plotting:
#' library(ggplot2)
#' p <- (ggplot(data.frame("X"=z[1,], "Y"=z[2,]), aes(x=X, y=Y))
#' + geom_point()
#' + ggtitle("Unsupervised data")
#' + xlab("D1")
#' + ylab("D2")
#' + theme_bw()
#' )
#' p
#'
#' c2plot <- factor(c)
#' levels(c2plot) <- c("4", "1", "3", "2")
#' pp <- (ggplot(data.frame("X"=z[1,], "Y"=z[2,], "Cluster"=as.character(c2plot)))
#' + geom_point(aes(x=X, y=Y, colour=Cluster, fill=Cluster))
#' #+ ggtitle("Slightly overlapping skew-normal simulation\n")
#' + xlab("D1")
#' + ylab("D2")
#' + theme_bw()
#' + scale_colour_discrete(guide=guide_legend(override.aes = list(size = 6, shape=22)))
#' + ggtitle("True clusters")
#' )
#' pp
#'}
#'
#'
DPMpost <- function (data, hyperG0, a=0.0001, b=0.0001, N, doPlot=TRUE,
nbclust_init=30, plotevery=floor(N/10),
diagVar=TRUE, verbose=TRUE,
distrib=c("gaussian", "skewnorm", "skewt"),
ncores = 1,
type_connec = "SOCK",
informPrior=NULL,
...
){
if(ncores>1){
if(ncores > parallel::detectCores()){
stop("Number of requested cores is higher than what is available")
}
}
if(ncores<2){
if(is.null(informPrior)){
res <- switch(distrib,
"gaussian"=DPMGibbsN(data, hyperG0, a, b, N, doPlot, nbclust_init, plotevery, diagVar,
verbose, ...),
"skewnorm"=DPMGibbsSkewN(data, hyperG0, a, b, N, doPlot, nbclust_init, plotevery, diagVar,
verbose, ...),
"skewt"=DPMGibbsSkewT(data, hyperG0, a, b, N, doPlot, nbclust_init, plotevery, diagVar,
verbose, ...)
)
}else{
res <- switch(distrib,
"gaussian"=DPMGibbsN_SeqPrior(data, informPrior, hyperG0, N,
nbclust_init, doPlot=doPlot, plotevery=plotevery,
diagVar=diagVar, verbose=verbose, ...),
"skewnorm"=stop("Skew normal distributions with informative prior is not implemented yet.\n",
"Contact the maintainer if you would like to see this feature implemented.\n",
"In the meantime, try the skew t distribution with 'skewt' which is a generalization ",
"of the skew normal distribution."),
"skewt"=DPMGibbsSkewT_SeqPrior(data, informPrior, hyperG0, N, nbclust_init,
doPlot=doPlot, plotevery=plotevery, diagVar=diagVar,
verbose=verbose, ...)
)
}
}else{
if(is.null(informPrior)){
if(distrib=="skewnorm"){
warning("Parallel implementation with skew normal distributions is not available yet.\n",
"Contact the maintainer if you would like to see this feature implemented.\n",
"In the meantime, the non-parallel implementation is being run instead")
}
res <- switch(distrib,
"gaussian"=DPMGibbsN_parallel(ncores, type_connec, data, hyperG0, a, b, N,
doPlot, nbclust_init, plotevery, diagVar,
verbose, ...),
"skewnorm"=DPMGibbsSkewN(data, hyperG0, a, b, N, doPlot, nbclust_init, plotevery, diagVar,
verbose, ...),
"skewt"=DPMGibbsSkewT_parallel(ncores, type_connec, data, hyperG0, a, b, N,
doPlot, nbclust_init, plotevery, diagVar,
verbose, ...)
)
}else{
warning("Parallel implementation with an informative prior for gaussian distributions is not available yet.\n",
"Contact the maintainer if you would like to see this feature implemented.\n",
"In the meantime, the non-parallel implementation is being run instead.")
res <- switch(distrib,
"gaussian"=DPMGibbsN_SeqPrior(data, informPrior, hyperG0, N,
nbclust_init, doPlot=doPlot, plotevery=plotevery,
diagVar=diagVar, verbose=verbose, ...),
"skewnorm"=stop("Skew normal distributions with informative prior is not implemented yet.\n",
"Contact the maintainer if you would like to see this feature implemented.\n",
"In the meantime, try the skew t distribution with 'skewt' which is a generalization ",
"of the skew normal distribution."),
"skewt"=DPMGibbsSkewT_SeqPrior_parallel(ncores, type_connec, data, informPrior,
hyperG0, N, nbclust_init, doPlot=doPlot,
plotevery=plotevery, diagVar=diagVar,
verbose=verbose, ...)
)
}
}
return(res)
}
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