avgByBin {IdeoViz} | R Documentation

## Aggregates data by genomic bins

### Description

Aggregates data by genomic bins

### Usage

    avgByBin(xpr, featureData, target_GR, justReturnBins = FALSE,
       getBinCountOnly = FALSE, FUN = mean, doSampleCor = FALSE,
       verbose = FALSE)

### Arguments

`featureData` | (data.frame or GRanges) Locus coordinates. Row order must match `xpr`. Column order should be: 1. chrom, 2. locus start, 3. locus end. All elements are assumed to be of identical width. Coordinates must be zero-based or one-based, but not half-open. Coordinate system must match that of `target_GR`.
`target_GR` | (GRanges) Target intervals, with coordinate system matching that of featureData.
`justReturnBins` | (logical) when TRUE, returns the coordinates of the bin to which each row belongs. Does not aggregate data in any way. This output can be used as input for more complex functions with data from each bin.
`getBinCountOnly` | (logical) when TRUE, does not aggregate or expect xpr. Only returns number of overlapping subject ranges per bin. Speeds up computation.
`FUN` | (function) function to aggregate data in bin
`doSampleCor` | (logical) set to TRUE to compute mean pairwise sample correlation (Pearson correlation) for each bin; when TRUE, this function overrides `FUN`.
`verbose` | (logical) print status messages
`xpr(data.frame` | or matrix) Locus-wise values. Rows correspond to genomic intervals (probes, genes, etc.,) while columns correspond to individual samples

### Details

Computed mean value of binned data. This function assumes that all elements in `featureData` have identical width. If provided with elements of disparate widths, the respective widths are not weighted averaging. This behaviour may change in future versions of IdeoViz. This function allows the user to bin data if this hasn't already been done, and is a step involved in preparing the data for `plotOnIdeo()`. This function computes binned within-sample average of probes overlapping the same range. Where a range overlaps multiple bins, it gets counted in all.

### Value

(GRanges) Binned data or binning statistics; information returned for non-empty bins only. The default for this function is to return binned data; alternately, if `justReturnBins=TRUE` or `getBinCountOnly=TRUE` the function will return statistics on bin counts. The latter may be useful to plot spatial density of the input metric.
The flags and output types are presented in order of evaluation precedence:

1. If `getBinCountOnly=TRUE`, returns a list with a single entry: bin_ID: (data.frame) bin information: chrom, start, end, width, strand, index, and count. "index" is the row number of target_GR to which this bin corresponds

2. If `justReturnBins=TRUE` and `getBinCountOnly=FALSE`, returns a list with three entries:

   1. bin_ID: same as bin_ID in output 1 above

   2. xpr:(data.frame) B-by-n columns where B is total number of [target_GR, featureData] overlaps (see next entry, binmap_idx) and n is number of columns in xpr; column order matches xpr. Contains sample-wise data "flattened" so that each [target,subject] pair is presented. More formally, entry [i,j] contains expression for overlap of row i from binmap_idx for sample j (where 1 <= i <= B, 1 <= j <= n)

   3. binmap_idx:(matrix) two-column matrix: 1) target_GR row, 2) row of featureData which overlaps with index in column 1. (matrix output of `GenomicRanges::findOverlaps())`)

3. Default: If `justReturnBins=FALSE` and `getBinCountOnly=FALSE`, returns a GRanges object. Results are contained in the `elementMetadata` slot. For a dataset with n samples, the table would have (n+1) columns; the first column is bin_count, and indicates number of units contained in that bin. Columns (2:(n+1)) contain binned values for each sample in column order corresponding to that of xpr.
   For `doSampleCor=TRUE`, result is in a metadata column with name "mean_pairwise"cor". Bins with a single datapoint per sample get a value of NA.

### See Also

`getIdeo()`, `getBins()`

### Examples

    ideo_hg19 <- getIdeo("hg19")
    data(GSM733664_broadPeaks)
    chrom_bins <- getBins(c("chr1","chr2","chrX"),
    	ideo_hg19,stepSize=5*100*1000)
    # default binning
    mean_peak <- avgByBin(data.frame(value=GSM733664_broadPeaks[,7]),
    GSM733664_broadPeaks[,1:3], chrom_bins)
    # custom function
    median_peak <- avgByBin(
    data.frame(value=GSM733664_broadPeaks[,7]),
    GSM733664_broadPeaks[,1:3], chrom_bins, FUN=median)
    # mean pairwise sample correlation
    data(binned_multiSeries)
    bins2 <- getBins(c("chr1"), ideo_hg19, stepSize=5e6)
    samplecor <- avgByBin(mcols(binned_multiSeries)[,1:3], binned_multiSeries, bins2, doSampleCor=TRUE)
    # just get bin count
    binstats <- avgByBin(data.frame(value=GSM733664_broadPeaks[,7]),
    GSM733664_broadPeaks[,1:3], chrom_bins, getBinCountOnly=TRUE)

[Package IdeoViz version 1.20.0 Index]