Speed issue when working with large bigwigs

[ammawla]

Large ATAC bigwigs cause severe bottlenecking when running epiRomics_track_layer/epiRomics_track_layer_human.

One solution could be to add in a function (wrapper for bash) to run on the initial dataset, where bigwig files are split by chromosome and saved in a temp directory, allowing for faster access.

Another solution could be to parallelize the bigwig processing, or find another package that is a bit more efficient.

[ammawla]

May need to replace rtracklayr import of bigwigs if another tool exists that can speed up position location.

Current working solution is to build in function that subsets bigwigs by chromosome, or by chunks (this could be a problem if transcript or gene model cross two chunks) and saves, prior to running visual tracks. Visualization function can then access each chunk for speed.