Likelihood_Ratio_Test: Defines the likelihood ratio test

In Colossus: "Risk Model Regression and Analysis with Complex Non-Linear Models"

Defines the likelihood ratio test

Description

Likelihood_Ratio_Test uses two models and calculates the ratio

Usage

Likelihood_Ratio_Test(alternative_model, null_model)

Arguments

alternative_model	the new model of interest in list form, output from a Poisson regression
null_model	a model to compare against, in list form

Value

returns the score statistic

Examples

library(data.table)
# In an actual example, one would run two seperate RunCoxRegression regressions,
#    assigning the results to e0 and e1
a <- c(0, 1, 2, 3, 4, 5, 6, 0, 1, 2, 3, 4, 5, 6)
b <- c(1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7)
c <- c(1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0)
d <- c(3, 4, 5, 6, 7, 8, 9, 1, 2, 1, 1, 2, 1, 2)
e <- c(1, 2, 0, 0, 1, 2, 0, 0, 1, 2, 0, 0, 1, 2)
df <- data.table("a" = a, "b" = b, "c" = c, "d" = d, "e" = e)
keep_constant <- c(0)
a_n <- c(-0.1, 0.1, 0.1, 0.2)
control <- list("ncores" = 1, "maxiter" = 10, "verbose" = 0)
model <- Cox(a, b, c) ~ plinear(d * d, 0) + loglinear(factor(e))
alternative_model <- CoxRun(model, df,
  control = control,
  a_n = a_n, keep_constant = c(0, 1, 0)
)
null_model <- CoxRun(Cox(a, b, c) ~ null(), df, control = control)
score <- Likelihood_Ratio_Test(alternative_model, null_model)

Colossus documentation built on Feb. 20, 2026, 5:10 p.m.