unscale: Unscale Parameters

In rBatt/trawlDiversity: Long-term changes in species richness along the North American coastline

Description

Unscale parameters from a polynomial multiple linear regression

Usage

unscale(a1, a2, a3, a4, a5, mu1, mu2, sigma1, sigma2)

Arguments

a1	intercept term
a2	coefficient for first predictor
a3	coefficient for first predictor squared
a4	cofficient for second predictor
a5	coefficient for second predictor squared
mu1	mean used to scale first predictor
mu2	mean used to scale second predictor
sigma1	standard deviation used to scale first predictor
sigma2	standard deviation used to scale second predictor

Details

Assume a model of the general form y ~ a1 + a2*x1 + a3*x1^2 + a4*x2 + a5*x2^2. Scaling is assumed to be scale(x1), e.g. All arguments can be vectors, for which each element should refer to a different model/ regression.

Created to unscale parameters used in an MSOM. In this case, each iteration on each chain effectively referes to a different set of parameters. So if the posterior was 100 iterations sampled, the 'a' arguments would be of length 100, and mu and sigma arguments could be length 1 (and recycled), or have the same value repeated 100 times. Alterntively, if the 'a' arguments refer to models for which the predictors were scaled differently, just make sure that the mu and sigma values are repeated to match to the corresponding models. No checking is done, but this should be fairly intuitive: the coefficients should match up with the scaling constants used to scale the predictors used in the model that estimated the coefficients.

Value

Either a vector (if a1 is of length 1) or a matrix (if a1 is longer than 1) of unscaled parameters.

rBatt/trawlDiversity documentation built on Aug. 14, 2021, 1:01 p.m.