Check model for violation of sphericity. For Bartlett's Test of Sphericity (used for correlation matrices and factor analyses), see check_sphericity_bartlett.
Arguments
- x
A model object.
- ...
Arguments passed to
car::Anova
.
Value
Invisibly returns the p-values of the test statistics. A p-value < 0.05 indicates a violation of sphericity.
Examples
if (require("car")) {
soils.mod <- lm(
cbind(pH, N, Dens, P, Ca, Mg, K, Na, Conduc) ~ Block + Contour * Depth,
data = Soils
)
check_sphericity(Manova(soils.mod))
}
#> Loading required package: car
#> Loading required package: carData
#>
#> Attaching package: ‘car’
#> The following object is masked from ‘package:rstanarm’:
#>
#> logit
#> The following object is masked from ‘package:psych’:
#>
#> logit
#> OK: Data seems to be spherical (p > .999).
#>