GC lambda

[EG]

Hi, 

Where can I find the formula for GC lambda at different percentiles? LocusZoom web app displays it ("Genomic Control lambda calculated based on the 50th percentile (median), 10th percentile, 1st percentile, and 1/10th of a percentile"). 

The formula 'median(qchisq(p, df=1, lower.tail=FALSE)) / qchisq(0.5, 1)' works for 50th percentile, but I am unable to modify it appropriately to match the values for other percentiles as displayed on the web app (an example: https://my.locuszoom.org/gwas/19554/).

Thanks

[locuszoom]

It is here: https://github.com/statgen/locuszoom-hosted/blob/d0a94e22e902de247531f019ef414041219ef4dc/util/ingest/qq.py#L172-L182