Possible correlates of percentile

diazrenata / scadsanalysis

Research compendium comparing species abundance distributions to their feasible sets.

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Possible correlates of percentile #20

Closed diazrenata closed 4 years ago

diazrenata commented 4 years ago

S, N, S/N
some measure of spread in the FS distribution. Not just range, as this will be sensitive to whether you happen on the very flat/very skewed ones. Sd or something.
mean/median of the FS distribution? If the central tendency is super skewed/super flat.
dataset

then, manips

diazrenata commented 4 years ago

I STRONGLY SUSPECT S/N, spread, and mean will be correlated with each other, which raises the question which one(s) to use as predictors for percentile.

diazrenata commented 4 years ago

Statistical approaches

lm
- pro: super straightforward, r2 computes automatically
- con: not actually appropriate for response variable bounded 0-1 (or 0-100); estimates go outside range of possible values AND fails to accommodate expected bunching up at the extremes
binomial glm
- pro: easy and automatically bendy
- con: r2?
beta regression
- pro: from googling, developed specifically for modeling probability as a response. Use coefficients and pseudo-R2? See https://cran.r-project.org/web/packages/betareg/vignettes/betareg.pdf
- con: ~looks bayesian (not freq),~ not sure how to implement or interpret (but learnable)

diazrenata commented 4 years ago

Beta regression can't handle 0 or 1, and I'm getting failures even when I fudged it (changed 0's to v small, etc)

Try zero-one inflated beta regression in brms? https://cran.r-project.org/web/packages/brms/vignettes/brms_families.html

diazrenata commented 4 years ago

These all covary so strongly with S and N I no longer have much confidence in teasing apart relationships.

diazrenata commented 4 years ago

I think it's worth doing a zero one inflated brms just to see if %ile value changes with S and N, or maybe N/S. We know there are complicated relationships between S and N and FS characteristics, but it is hard to tell if there's really any cascading effecton %iles.