easystats / easystats/performance
Possible error in r2_xu in performance
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Description
Hello,
I just wanted to briefly point out that, in my opinion, r2_xu in performance might not be correctly specified; to me it looks like the function calculates an omega as given in equation (6) of Xu (2003; 0.1002/sim.1572), altough this equation seems to be only for null models. In the current version r2_xu is calculated as follows:
r2_xu <- 1 - stats::var(stats::residuals(model, verbose = FALSE))/stats::var(insight::get_response(model, verbose = FALSE))
This means that the variance of the residuals of the model with covariates is devided by the variance of the reponse (equation 6), not by the residual variance of the null model (as in equation 5).
Of course I might also get it wrong?
Best wishes
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Research direction
Start at the r2_xu calculation quoted in the issue and read the surrounding performance implementation. Compare it with equations (5) and (6) of Xu (2003); done means the applicable definition is established and the implementation and regression coverage reflect it.
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Assessment
- Tech stack
- r
- Domain
- data
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100