R/profileCGH.getRegions.R

In aroma.affymetrix: Analysis of Large Affymetrix Microarray Data Sets

setMethodS3("getRegions", "profileCGH", function(this, nbrOfSnps=c(1,Inf), smoothing=NULL, ...) {
  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  # Validate arguments
  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  # Argument 'nbrOfSnps':
  if (length(nbrOfSnps) == 1)
    nbrOfSnps <- c(nbrOfSnps,Inf)

  # Argument 'smoothing':
  if (!is.null(smoothing) & !is.matrix(smoothing)) {
    smoothing <- matrix(smoothing, ncol=2, byrow=TRUE)
  }

  pv <- this$profileValues
  stdvs <- this$SigmaC$Value

  hasUnits <- (!is.null(pv$chipType) && !is.null(pv$units))
  if (hasUnits) {
    chipType <- as.character(pv$chipType)
    chipType <- gsub("[,-]monocell$", "", chipType)

    rsIds <- character(nrow(pv))
    unitNames <- character(nrow(pv))
    for (cc in unique(chipType)) {
      cdf <- AffymetrixCdfFile$byChipType(cc)

      idxs <- which(chipType == cc)
      unitNames[idxs] <- getUnitNames(cdf, units=pv$units[idxs])
    }
  }

  rsIds <- NULL

  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  # Allocate result table
  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  # Identify unique regions
  uRegions <- unique(pv$Region)
  nbrOfRegions <- length(uRegions)

  # Columns
  colClasses <- c(Chromosome="character", start="integer", 
                   stop="integer", length="integer", nbrOfSnps="integer", 
                                       Smoothing="double", SNRtoZero="double")
  if (hasUnits) {
    colClasses <- c(colClasses, firstSnp="character", lastSnp="character")
    if (!is.null(rsIds))
      colClasses <- c(colClasses, firstRsId="character", lastRsId="character")
  }

  df <- dataFrame(colClasses, nrow=nbrOfRegions)


  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  # Extract each region
  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  for (rr in seq_along(uRegions)) {
    # Get the region ID
    region <- uRegions[rr]

    # Get the first and last position of each region
    idx <- which(region == pv$Region)
    idx <- idx[c(1,length(idx))]

    # Chromosome
    df[rr,"Chromosome"] <- pv$Chromosome[idx[1]]

    # (start, stop, length)
    df[rr,c("start", "stop")] <- as.integer(pv$PosBase[idx])
    df[rr,"length"] <- as.integer(diff(pv$PosBase[idx]))

    # Number of SNPs
    df[rr,"nbrOfSnps"] <- as.integer(diff(idx)+1)

    # Smoothing
    df[rr,"Smoothing"] <- pv$Smoothing[idx[1]]

    # Signal-to-noise ratio
    df[rr,"SNRtoZero"] <- abs(df[rr,"Smoothing"]) / stdvs

    # Gain, normal, or loss?
#    levels <- c("loss", "normal", "gain")
#    levels <- c("-", "0", "+")
#    df[rr,"GNL"] <- levels[pv$ZoneGNL[idx[1]]+2]

    if (hasUnits) {
      # Get the SNP names
      df[rr,c("firstSnp", "lastSnp")] <- unitNames[idx]

      # Get the rsIds 
#      if (!is.null(rsIds))
#        df[rr,c("firstRsId", "lastRsId")] <- allRsIds[subset[idx]]
# 'allRsIds', 'subset'?!? /HB 2007-06-11
    }
  }

  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  # Filter
  # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  # Gain, normal, or loss
#  if (!is.null(gnl)) {
#    keep <- (df$GNL %in% gnl)
#    df <- df[keep,]
#  }

  # Number of SNPs
  if (!is.null(nbrOfSnps)) {
    keep <- (nbrOfSnps[1] <= df$nbrOfSnps & df$nbrOfSnps <= nbrOfSnps[2])
    df <- df[keep,]
  }

  # Smoothing regions
  if (!is.null(smoothing)) {
    keep <- rep(FALSE, nrow(df))
    for (kk in seq_len(nrow(smoothing))) {
      range <- smoothing[kk,]
      keep <- keep | (range[1] <= df$Smoothing & df$Smoothing <= range[2])
    }
    df <- df[keep,]
  }

  df
}, private=TRUE)