arrangeSideBySide       Helper function to arrange two trellis objects
                        side by side on a grid.
centromere              Coordinates of centromere
chromosomeAnnotation    chromosome annotation
cytoband                Start and stop sites of cytoband
plotIdiogram            Plots idiogram for one chromosome
xypanel                 A panel function for plotting copy number
                        versus physical position
xyplot                  Plot copy number and physical position for a
                        set of genomic intervals.
