Extract the fixed effects from a GAMM

Source: R/extract_fixed.R

When using a GAM for mixed models, we may have specific interest in the fixed effect parameters.

extract_fixed(model, ci_level = 0.95, digits = 3, ...)

Arguments

model

A gam or bam model
ci_level

Level for the confidence interval. Must be between 0 and 1.
digits

Rounding for the output.
...

Passed to summary.gam, e.g. to set re.test = FALSE.

Value

A data.frame with the coefficients, standard error, and upper and lower bounds.

Details

This essentially reproduces the 'parametric' output from summary.gam.

See also

fixef

Examples


library(mgcv)

#> Loading required package: nlme
#> This is mgcv 1.8-33. For overview type 'help("mgcv-package")'.
library(lme4)

#> Loading required package: Matrix
#> 
#> Attaching package: ‘lme4’
#> The following object is masked from ‘package:nlme’:
#> 
#>     lmList

lmer_model <- lmer(Reaction ~ Days + (Days || Subject), data = sleepstudy)
ga_model <- gam(Reaction ~ Days + s(Subject, bs = "re") + s(Days, Subject, bs = "re"),
  data = sleepstudy,
  method = "REML"
)

fixef(lmer_model)

#> (Intercept)        Days 
#>   251.40510    10.46729 
extract_fixed(ga_model)

#> # A tibble: 2 x 7
#>   term      value    se     t     p lower_2.5 upper_97.5
#>   <chr>     <dbl> <dbl> <dbl> <dbl>     <dbl>      <dbl>
#> 1 Intercept 251.   6.88 36.5      0    238.        265. 
#> 2 Days       10.5  1.56  6.71     0      7.39       13.5