# Lambda for qq plot

**URL:** <https://discuss.hail.is/t/lambda-for-qq-plot/749>\
**Category:** Feature Requests\
**Created:** [November 5, 2018, 5:58pm UTC](https://discuss.hail.is/t/lambda-for-qq-plot/749 "2018-11-05T17:58:56Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jjfarrell](https://yyz2.discourse-cdn.com/flex036/user_avatar/discuss.hail.is/jjfarrell/32/108_2.png) [@jjfarrell](https://discuss.hail.is/u/jjfarrell)\
**Post date:** [November 5, 2018, 5:58pm UTC](https://discuss.hail.is/t/lambda-for-qq-plot/749/1 "2018-11-05T17:58:57Z")

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It would be very useful to include the lambda (also known as the genomic inflation factor) for the Hail qq plot. λ is defined as the median of the resulting chi-squared test statistics divided by the expected median of the chi-squared distribution. Values near 1 indicate no inflation.

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**Author:** ![tpoterba](https://yyz2.discourse-cdn.com/flex036/user_avatar/discuss.hail.is/tpoterba/32/61_2.png) [@tpoterba](https://discuss.hail.is/u/tpoterba)\
**Post date:** [November 5, 2018, 6:10pm UTC](https://discuss.hail.is/t/lambda-for-qq-plot/749/2 "2018-11-05T18:10:56Z")

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Good idea. We need approximate quantile aggregators before we can do this efficiently, though.