MACS2 parameters slocal and llocal - how are they related to open chromatin?

Question

[Pei]

Hello everyone!

I found this text from MACS2 document

By default, MACS considers 1000bp for small local region(--slocal), and 10000bps for large local region(--llocal) which captures the bias from a long-range effect like an open chromatin domain.

Could anyone please help provide some more explanation?

I guess that this means that if an open chromatin domain was encountered, it would be better for MACS2 to compute a local lambda by scanning a larger local region, rather than a small one. If not an open chromatin, scanning a small local region should be good enough.

Am I right?

Thanks!