Plot likelihood function

Plot a likelihood function showing relative likelihood or deviance, with optional confidence intervals and reference lines.

# S3 method for class 'likelihood_function'
plot(x, parameter = NULL,
  type = c("likelihood", "deviance", "both"), n_points = 200,
  interval = NULL, add_ci = TRUE, ci_level = 0.95, add_mle = TRUE,
  relative = TRUE, main = NULL, xlab = NULL, ylab = NULL,
  col = "black", lwd = 2, ...)

# S3 method for class 'likelihood_function'
plot(x, parameter = NULL,
  type = c("likelihood", "deviance", "both"), n_points = 200,
  interval = NULL, add_ci = TRUE, ci_level = 0.95, add_mle = TRUE,
  relative = TRUE, main = NULL, xlab = NULL, ylab = NULL,
  col = "black", lwd = 2, ...)

Arguments

x

A likelihood_function object

parameter

Name of the parameter to plot. If NULL, plots the first parameter and displays a message.

type

Type of plot: "likelihood" (relative likelihood), "deviance" (profile deviance), or "both" (two-panel plot)

n_points

Number of parameter values at which to evaluate the profile likelihood

interval

A length-2 numeric vector specifying the range of parameter values to plot. If NULL, automatically determined as ±5 standard errors from the MLE.

add_ci

Logical; if TRUE, adds confidence interval bounds to the plot

ci_level

Confidence level for the intervals (default: 0.95)

add_mle

Logical; if TRUE, adds a vertical line at the MLE

relative

Logical; if TRUE, plots relative likelihood; if FALSE, plots absolute likelihood. Only applies to likelihood plots.

main

Main title for the plot. If NULL, automatically generated.

xlab

X-axis label. If NULL, uses the parameter name.

ylab

Y-axis label. If NULL, automatically determined by plot type.

col

Color for the main likelihood/deviance curve

lwd

Line width for the main curve

...

Additional arguments passed to plot

Value

Invisibly returns the profile likelihood data frame

Details

Creates publication-quality plots of likelihood and deviance functions. Includes optional confidence intervals and reference lines. For two-panel plots, the layout is automatically managed.

See also

ggplot_likelihood for ggplot2 version, plotly_likelihood for interactive plots