Influence plot

A bubble plot of leverage against the studentised residuals, with bubble area proportional to Cook's distance. It summarises in a single picture which observations most influence a fitted model. Reference lines mark large residuals and high-leverage points, and the most influential observations are labelled.

Usage

influence_plot(model, n_label = 3, colour = depictr_brand(), title = NULL)

Arguments

model

A fitted lm or glm model.

n_label

Number of most-influential points (by Cook's distance) to label.

colour

Bubble colour. Defaults to the depictr brand blue.

title

Plot title.

Value

A ggplot2::ggplot object.

References

Cook RD (1977). “Detection of influential observation in linear regression.” Technometrics, 19(1), 15–18. doi:10.1080/00401706.1977.10489493 .

Examples

fit <- lm(yield ~ rainfall + fertiliser + soil_ph, data = crop_yield)
influence_plot(fit)