PLINK - tutorial - PRS calculation

Question

[beginner123]

Can someone explain me why they make a null.r2? what is the goal of this? And what does it give me? I'd like to kindly refer to this website that I'm using in order to calculate my PRS. https://choishingwan.github.io/PRS-Tutorial/plink/

Answer 1

[Sam]

null R2 is the R2 of the model without the PRS. This allow us to calculate the contribution of just the PRS, without the covariates