plot3d.lm: Method for plotting simple linear fit.

Description

This function provides several plots of the result of fitting a two-predictor model.

Usage

# S3 method for lm
plot3d(x, 
       which = 1, 
       plane.col = "gray", plane.alpha = 0.5,
       sharedMouse = TRUE, 
       use_surface3d, 
       do_grid = TRUE,
       grid.col = "black", 
       grid.alpha = 1,
       grid.steps = 5,
       sub.steps = 4,
       vars = get_all_vars(terms(x), x$model),
       ...)

Arguments

An object inheriting from class "lm" obtained by fitting a two-predictor model.

which

Which plot to show? See Details below.

plane.col, plane.alpha

These parameters control the colour and transparency of a plane or surface.

sharedMouse

If multiple plots are requested, should they share mouse controls, so that they move in sync?

use_surface3d

Use the surface3d function to plot the surface rather than planes3d. This allows curved surfaces to be shown. The default is FALSE if the model looks like a simple 2 parameter linear fit, otherwise TRUE.

do_grid

Plot a grid.

grid.col, grid.alpha, grid.steps

Characteristics of the grid.

sub.steps

If use_surface3d is TRUE, use an internal grid of grid.steps*sub.steps to draw the surface. sub.steps > 1 allows curvature within facets. Similarly, if do_grid is TRUE, it allows curvature within grid lines.

vars

A dataframe containing the variables to plot in the first three columns, with the response assumed to be in column 1. See the Note below.

…

Other parameters to pass to the default plot3d method, to control the appearance of aspects of the plot other than the plane.

Value

Called for the side effect of drawing one or more plots.

Invisibly returns a high-level vector of object ids. Names of object ids have the plot number (in drawing order) appended.

Details

Three plots are possible, depending on the value(s) in which:

(default) Show the points and the fitted plane.
Show the residuals and the plane at z = 0.
Show the predicted values on the fitted plane.

Examples

Run this code

# NOT RUN {
open3d()
ids <- plot3d(lm(mpg ~ wt + qsec, data = mtcars), which = 1:3)
names(ids)

open3d()
plot3d(lm(mpg ~ wt + I(wt^2) + qsec, data = mtcars))

open3d()
# Specify vars in the order:  response, pred1, pred2.
plot3d(lm(mpg ~ poly(wt, 3) + qsec, data = mtcars), 
       vars = mtcars[,c("mpg", "wt", "qsec")])
# }