zoomChromosome: Interactive plot of a single chromsome
Description
  Plot splitting the screen into two.  The top windows displays the
  entire chromosome, whilst the bottom plots a selected region.  The plot
  is interactive allowing the user to click twice on a chromosome in the upper
  plot and have it the region between the two clicks displayed below.
Usage
zoomChromosome(..., array = 1, chrom.to.plot, colors = NULL, chrominfo =
chrominfo.Mb, ylim = c(-2, 2))
Arguments
array
Specify which array should be plotted.
chrom.to.plot
Which chromosome should be plotted
colors
Vector specify the colors for each of the SegLists
chrominfo
chromosomal information associated with the
	  mapping of the data.
ylim
Specify the limits of the y-axis
Details
  If colors is unspecified then all SegLists passed to this function will
  be plotted in blue.  Since this makes it quite hard to tell which is
  which it is highly recommended to specify the colors vector if more
  than one object is being passe to this function.