R/lefseformat.R

In KonradZych/SIAMCAT: Statistical Inference of Associations between Microbial Communities And host phenoTypes

#!/usr/bin/Rscript
### SIAMCAT - Statistical Inference of Associations between
### Microbial Communities And host phenoTypes R flavor EMBL
### Heidelberg 2012-2018 GNU GPL 3.0

#' @title create a lefse input file from siamcat object
#' 
#' @description This function creates a lefse input file from siamcat object
#' 
#' @param siamcat object of class \link{siamcat-class}
#' 
#' @param filename name of the input file to which data will be save
#' 
#' @keywords siamcat.to.lefse
#' 
#' @return nothing but data is written to a file
#' 
#' @examples
#' 
#' data(siamcat_example)
#' siamcat.to.lefse(siamcat_example)
#' 
#' @export
#' 
siamcat.to.lefse <- function(siamcat, filename="siamcat_output.txt") {
    feat   <- get.features.matrix(siamcat)
    label  <- label(siamcat)
    labelD <- label$label
    labelD[label$p.idx] <- label$p.lab
    labelD[label$n.idx] <- label$n.lab

    results <- rbind(labelD,
                        colnames(feat),
                        feat)

    rownames(results) <- c("label",
                            "sample_id",
                            rownames(feat))

    write.table(results,
                file = filename,   
                quote = FALSE, 
                sep = '\t', 
                row.names = TRUE,
                col.names = FALSE)
}

#' @title read an input file in a LEfSe input format
#' 
#' @description This reads an input file in a LEfSe input format
#'  
#' @param filename name of the input file in a LEfSe input format
#' 
#' @param rows.meta specifies in which rows medata variables are stored
#'
#' @param row.samples specifies in which row sample names are stored
#'
#' @keywords read.lefse
#' 
#' @return a list with two elements: \itemize{
#'     \item \code{feat} a features matrix (just as returned by 
#'     \link{read.features} function
#'     \item \code{meta} a metadate matrix (just as returned by 
#'     \link{read.meta} function}
#' @examples
#' 
#' fn.in.lefse<- system.file("extdata",
#' "LEfSe_crc_zeller_msb_mocat_specI.tsv",package = "SIAMCAT")
#' meta.and.features <- read.lefse(fn.in.lefse, rows.meta = 1:6, 
#' row.samples = 7)
#' meta <- meta.and.features$meta
#' feat <- meta.and.features$feat
#' label <- create.label.from.metadata(meta, "label", case = "cancer")
#' siamcat <- siamcat(feat, label, meta)
#' 
#' @export
#' 
read.lefse <- function(filename="data.txt", rows.meta = 1, row.samples = 2) {

    lefse <- read.csv(filename, sep = "\t", header = FALSE, 
                        stringsAsFactors = FALSE)
    
    meta          <- lefse[rows.meta,]
    samples.names <- lefse[row.samples,]
    feat          <- lefse[(max(c(rows.meta,row.samples))+1):nrow(lefse),]
    
    rownames(meta) <- meta[,1]
    meta <- meta[,-1]
    colnames(meta) <- samples.names[,-1]
    meta <- sample_data(as.data.frame(t(meta)))
    
    rownames(feat) <- feat[,1]
    feat <- feat[,-1]
    colnames(feat) <- samples.names[,-1]
    feat <- apply(feat,c(1,2),as.numeric)
    feat <- otu_table(feat,taxa_are_rows = TRUE)
    
    return(list(feat = feat, meta = meta))
}