Skip to contents

Plot MID Conditional Expectations with ggplot2

Source: R/ggmid_mid_conditional.R
ggmid.mid.conditional.Rd

For "mid.conditional" objects, ggmid() visualizes Individual Conditional Expectation (ICE) curves derived from a fitted MID model.

Usage

# S3 method for class 'mid.conditional'
ggmid(
  object,
  type = c("iceplot", "centered"),
  theme = NULL,
  term = NULL,
  var.alpha = NULL,
  var.color = NULL,
  var.linetype = NULL,
  var.linewidth = NULL,
  reference = 1L,
  dots = TRUE,
  sample = NULL,
  ...
)

# S3 method for class 'mid.conditional'
autoplot(object, ...)

Arguments

object

a "mid.conditional" object to be visualized.

type

the plotting style. One of "iceplot" or "centered".

theme

a character string or object defining the color theme. See color.theme for details.

term

an optional character string specifying an interaction term. If passed, the ICE curve for the specified term is plotted.

var.alpha

a variable name or expression to map to the alpha aesthetic.

var.color

a variable name or expression to map to the color aesthetic.

var.linetype

a variable name or expression to map to the linetype aesthetic.

var.linewidth

a variable name or expression to map to the linewidth aesthetic.

reference

an integer specifying the index of the sample points to use as the reference for centering the c-ICE plot.

dots

logical. If TRUE, points representing the actual predictions for each observation are plotted.

sample

an optional vector specifying the names of observations to be plotted.

...

optional parameters passed on to the main layer.

Value

ggmid.mid.conditional() returns a "ggplot" object.

Details

This is an S3 method for the ggmid() generic that produces ICE curves from a "mid.conditional" object. ICE plots are a model-agnostic tool for visualizing how a model's prediction for a single observation changes as one feature varies. This function plots one line for each observation in the data.

The type argument controls the visualization style: The default, type = "iceplot", plots the raw ICE curves. The type = "centered" option creates the centered ICE (c-ICE) plot, where each curve is shifted to start at zero, making it easier to compare the slopes of the curves.

The var.color, var.alpha, etc., arguments allow you to map aesthetics to other variables in your data using (possibly) unquoted expressions.

See also

mid.conditional, ggmid, plot.mid.conditional

Examples

data(airquality, package = "datasets")
library(midr)
mid <- interpret(Ozone ~ .^2, airquality, lambda = 0.1)
#> 'model' not passed: response variable in 'data' is used
ice <- mid.conditional(mid, "Temp", data = airquality)

# Create an ICE plot, coloring lines by 'Wind'
ggmid(ice, var.color = "Wind")


# Create a centered ICE plot, mapping color and linetype to other variables
ggmid(ice, type = "centered", theme = "Purple-Yellow",
      var.color = factor(Month), var.linetype = Wind > 10)