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However, sometimes it would be useful to be able to stretch-zoom tracks independently of each other, i.e., increase the relative height of one track while compressing the remaining tracks by equal amounts.
For example, imaging consider a track that has many reads aligned onto a gene. It would be useful to be able to force that track to stack its reads into a smaller vertical space, thus allowing the user to view the data without the more populous read alignments track seeming to crush or smash other tracks. We already have something of this implemented already - users can click a "-" icon in the upper left of a track to collapse all features into a single row.
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Re-packing to fit available vertical space, but no more
Often, when we zoom in on a single gene, it is useful to be able to eliminate empty vertical space in a gene model track. more to come later
Ordered and sorted stacking
more to come later