Is this a variation on a residual plot?

[Ikaros]

Hi all,

Consider the scatter plot below (example only):

The bottom subplot looks like a residual plot (y-x), but it's over (1+x). I'm hoping someone can explain what this is and the benefit of it.

Thanks

 

[mfb]

Maybe the uncertainty is expected to scale with 1+x?

 

[Ikaros]

Based on what type of data it is, I think you're correct. Thanks.