Applr: Tools for Visualizing and Explaining Linear Models

Applr is a small R package that makes it easy to visualize slices of higher-dimensional linear models and to present model equations clearly. It includes base R and ggplot2 helpers, plus an interactive 3D view for models with two predictors.

Details

Core capabilities:

• 2D slices of multi-variable models in base graphics

• ggplot2 layer for plotting model slices across facets

• Interactive 3D scatter with fitted surface (two predictors)

• Quick text/LaTeX equations from lm() objects

Main functions

• autoplot: autoplot.lm

• Base graphics: slice_2d, add_slice_2d

• ggplot2 layer: geom_slice (built on StatSlice and GeomSlice)

• ggplot2 labeling: geom_slice_text, geom_slice_subtitle, geom_slice_caption

• 3D visualization: scatter_3d

• Equations: lm_equation, lm_latex

Quick start

Fit a model, then see it in one call:

library(Applr)
model <- lm(mpg ~ qsec + am, data = mtcars)
autoplot(model)

Or build the plot yourself with a geom_slice() layer:

library(ggplot2)
model <- lm(hwy ~ displ * drv + cyl, data = mpg)
ggplot(mpg, aes(displ, hwy, color = drv)) +
  geom_point() +
  geom_slice(model, band = TRUE) +
  geom_slice_text() +
  geom_slice_subtitle()

See also

• Function help pages: ?slice_2d, ?geom_slice, ?scatter_3d, ?lm_equation, ?lm_latex

• The package README for a brief tour

Author

Maintainer: James Beeson jamesbeeson01@gmail.com

Authors:

• Cameron McClellan cameron.m.mcclellan@gmail.com

Other contributors:

• Garrett Saunders saundersg@byui.edu [thesis advisor]