plotPeak: Plot peak
In DBChIP: Differential Binding of Transcription Factor with ChIP-seq

Plot the coverage profile of differentially bound peaks

1	plotPeak(rept, dat, lib.size = NULL, w = 400, ext = 200, combine.rep = FALSE, cap = NULL, n.row.per.page = 6, caption = NULL)

`rept`	a data.frame as the result of `report.peak`.
`dat`	a list with the following items: chip.list, input.list, matching.input.names, norm.factor.vec. Description of the items can be found in the return value of `DBChIP`.
`lib.size`	a vector of library size of each ChIP sample. Used to scale profiles so that they are comparable.
`w`	half window size to plot around the binding sites.
`ext`	extension size for each read. Each read is extended from its 5' end by `ext` towards 3' end. If `ext` is set to 1, the minimum, per nucleotide read counts will be plotted.
`combine.rep`	logical, whether to combine replicates for the plot. Can be useful when there are too many replicates to plot.
`cap`	the maximum number of reads per nucleotide allowd to plot.
`n.row.per.page`	the maximum number of tracks (rows) per page.
`caption`	additional caption to appear on the title besides the location.