R/GenericTabularFileSet.calculateAverageColumnAcrossFiles.R

In aroma.core: Core Methods and Classes Used by 'aroma.*' Packages Part of the Aroma Framework

setMethodS3("calculateAverageColumnAcrossFiles", "GenericTabularFileSet", function(this, method=c("mean", "median"), na.rm=TRUE, ..., ram=NULL, force=FALSE, verbose=FALSE) {
  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  # Validate arguments
  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  # Argument 'this':
  nbrOfFiles <- length(this)
  if (nbrOfFiles == 0L) {
    throw("Cannot calculate average across data files. No data files in data set: ", getFullName(this))
  }

  # Argument 'method':
  method <- match.arg(method)

  # Argument 'ram':
  ram <- getRam(aromaSettings, ram)

  # Argument 'verbose':
  verbose <- Arguments$getVerbose(verbose)
  if (verbose) {
    pushState(verbose)
    on.exit(popState(verbose))
  }

  verbose && enter(verbose, "Estimating average column across arrays")
  verbose && cat(verbose, "Averaging method: ", method)
  verbose && cat(verbose, "na.rm: ", na.rm)


  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  # Check cached results
  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  dataSet <- getFullName(this)
  chipType <- getChipType(this)
  key <- list(dataSet=dataSet, chipType=chipType, fullnames=getFullNames(this), method=method, na.rm=na.rm)
  dirs <- c("aroma.affymetrix", dataSet, chipType)
  if (!force) {
    res <- loadCache(key=key, dirs=dirs)
    if (!is.null(res)) {
      verbose && cat(verbose, "Cached results found.")
      verbose && exit(verbose)
      return(res)
    }
  }


  if (method == "mean") {
    rowFcn <- rowMeans
  } else if (method == "median") {
    rowFcn <- rowMedians
  }

  verbose && cat(verbose, "Number of files: ", nbrOfFiles)

  df <- getOneFile(this)
  nbrOfRows <- nbrOfRows(df)
  units <- seq_len(nbrOfRows)
  nbrOfRows <- length(units)
  verbose && cat(verbose, "Number of rows: ", nbrOfRows)

  nbrOfRowsPerChunk <- ram*50e6
  chunkSize <- ceiling(nbrOfRowsPerChunk/nbrOfFiles)

  verbose && cat(verbose, "Number of rows per chunk: ", chunkSize)

  unitChunks <- splitInChunks(units, chunkSize=chunkSize)
  # Not needed anymore
  units <- NULL

  res <- lapply(unitChunks, FUN=function(units) {
    data <- extractMatrix(this, units=units, ...)
    est <- rowFcn(data, na.rm=na.rm)
    # Sanity check
    .stop_if_not(length(est) == length(units))
    est
  })
  # Not needed anymore
  unitChunks <- NULL

  res <- unlist(res, use.names=FALSE)
  verbose && str(verbose, res)

  # Sanity check
  .stop_if_not(length(res) == nbrOfRows)

  saveCache(res, key=key, dirs=dirs)

  verbose && exit(verbose)

  res
}, protected=TRUE)