glance.anova: Glance at a(n) anova object

In broom: Convert Statistical Objects into Tidy Tibbles

Glance at a(n) anova object

Description

Glance accepts a model object and returns a tibble::tibble() with exactly one row of model summaries. The summaries are typically goodness of fit measures, p-values for hypothesis tests on residuals, or model convergence information.

Glance never returns information from the original call to the modeling function. This includes the name of the modeling function or any arguments passed to the modeling function.

Glance does not calculate summary measures. Rather, it farms out these computations to appropriate methods and gathers the results together. Sometimes a goodness of fit measure will be undefined. In these cases the measure will be reported as NA.

Glance returns the same number of columns regardless of whether the model matrix is rank-deficient or not. If so, entries in columns that no longer have a well-defined value are filled in with an NA of the appropriate type.

Usage

## S3 method for class 'anova'
glance(x, ...)

Arguments

x

An anova object, such as those created by stats::anova(), car::Anova(), car::leveneTest(), or car::linearHypothesis().

...

Additional arguments. Not used. Needed to match generic signature only. Cautionary note: Misspelled arguments will be absorbed in ..., where they will be ignored. If the misspelled argument has a default value, the default value will be used. For example, if you pass conf.lvel = 0.9, all computation will proceed using conf.level = 0.95. Two exceptions here are: tidy() methods will warn when supplied an exponentiate argument if it will be ignored. augment() methods will warn when supplied a newdata argument if it will be ignored.

Value

A tibble::tibble() with exactly one row and columns:

deviance	Deviance of the model.
df.residual	Residual degrees of freedom.

Note

Note that the output of glance.anova() will vary depending on the initializing anova call. In some cases, it will just return an empty data frame. In other cases, glance.anova() may return columns that are also common to tidy.anova(). This is partly to preserve backwards compatibility with early versions of broom, but also because the underlying anova model yields components that could reasonably be interpreted as goodness-of-fit summaries too.

See Also

glance()

Other anova tidiers: glance.aov(), tidy.TukeyHSD(), tidy.anova(), tidy.aov(), tidy.aovlist(), tidy.manova()

Examples

# fit models
a <- lm(mpg ~ wt + qsec + disp, mtcars)
b <- lm(mpg ~ wt + qsec, mtcars)

mod <- anova(a, b)

# summarize model fit with tidiers
tidy(mod)
glance(mod)

# car::linearHypothesis() example
library(car)
mod_lht <- linearHypothesis(a, "wt - disp")
tidy(mod_lht)
glance(mod_lht)

broom documentation built on Sept. 30, 2024, 9:29 a.m.