Questions tagged [concurvity]

Concurvity refers to the nonlinear dependencies among covariates in an additive model, and is related to the concept of collinearity among predictors in a linear model. This tag should be used when a question is related to (multi)collinearity in the predictors of a model where the model contains smooth functions of covariates such as generalized additive models.

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interpretation of estimate concurvity vs worst concurvity in GAMs

I was wondering if there is someone who could explain (in conceptual terms) how to interpret estimate concurvity in a GAM implemented with mgcv and how it differs from worst concurvity (as obtained ...
• 119
156 views

High concurvity/ collinearity between time and temperature in GAM predicting deaths but low ACF. Does this matter?

I have problems with concurvity in my thesis research, and don't have access to a statistician who works with time series, GAMs or R. I'd be very grateful for any (partial) answer, however short. I'll ...
• 119
57 views

assessing impact of concurvity in GAM using time series of weather and mortality data

I have some questions about concurvity in a GAM using time series weather and mortality data (for details and model output see below). I'd be really appreciative of some help as most questions about ...
• 119
118 views

How to interpret concurvity and wiggliness induced by low or high K knots in GAM models

Two questions: 1. Concurvity for factors =1, is this normal? 2. How do you interpret a partial effect when the effect is linear and lines for confidence intervals are pinched at 0? Is it okay for ...
• 49
30 views

GAM with the same variable in both fixed and random

I have a dataset collected over multiple years, with many samples collected per year. The samples are assumed be random within year (collected over a short period of time, over a large area, in a ...
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59 views

High concurvity with random effect terms in generalized additive mixed effects models GAMM

I have a quick question concerning concurvity in a generalized additive mixed effects model. There are wonderful aids for identifying concurvity for GAMs not containing random effects. However, I have ...
217 views

GAM: Do shrinkage smooth splines also address for concurvity?

I have a gam model with automatic predictor selection based on cubic splines (bs = cr) and SELECT == T or shrinkage cubic splines (bs = cs) and SELECT == F. Now I'm wondering if predictors affected ...
224 views

Is it okay to ignore concurvity on our GAM model?

I'm trying to model a relationship between marine debris concentration (item/m^2) with several covariates using GAM with MGCV R package. I found that the concurvity values at worst-case scenario are ...
126 views

GAM concurvity measures greater than 1

I am currently using a gam modelling approach to describe the effects of several variables (es_sum, nat_sum, sect_sum, and prop_spec) on another variable (btwn). Each of es_sum, nat_sum, sect_sum, and ...
228 views

Variance components of a penalized spatial GAM have very large confidence intervals

I am working through a spatial GAM example in one of Simon Wood's lectures (found here), and ran into some problems surrounding concurvity and penalization. I've read a number of other posts on ...
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1 vote
138 views

concurvity in presence of random smooths [closed]

I am trying to fit a GAMM containing per subject random smooths using the bam function in mgcv as follows: ...
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187 views

When using GAMs, how much concurvity is too much?

Is there a rule of thumb for excessive concurvity? For example, I've heard that a VIF of $>10$ suggests that multicollinearity may be a problem (e.g., in this CV answer), but I cannot find a ...
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