Plot interpretation

Modelle zur Korrelations- und Regressionsanalyse

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lisa52625
Beiträge: 1
Registriert: Sa Jul 11, 2020 10:12 am

Plot interpretation

Beitrag von lisa52625 »

R Plot.PNG
I don't know how to interprete this plot.

Help would be appreciated! Thanks!
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EDi
Beiträge: 1599
Registriert: Sa Okt 08, 2016 3:39 pm

Re: Plot interpretation

Beitrag von EDi »

It shows fitted values vs residuals, likely from a gaussian linear model.

We see distinct lines, indicating that y is discrete (?), e.g. counts?

The lower border indicates that y has a lower bound (e.g. counts or positive only data.

The fan shape indicates a positive mean-variance relationship.

All three indicate that the gaussian linear model might be not a good representation.

A log-transformation of y could fix this.

I'd prefer a GLM with Gamma (for positive continuous y) or poisson / negative-binomial (depending on mean-variance-relationship) distribution. In both cases likely with a log-link function.

HTH,

Edi
Bitte immer ein reproduzierbares Minimalbeispiel angeben. Meinungen gehören mir und geben nicht die meines Brötchengebers wieder.

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