R code to get Log-likelihood for Binary logistic regression

Question

I have developed a binomial logistic regression using glm function in R. I need three outputs which are Log likelihood (no coefficients) Log likelihood (constants only) Log likelihood (at optimal)

What functions or packages do I need to obtain these outputs?

Answer 1

Say we have a fitted model m.

log-likelihood of full model (i.e., at MLE): logLik(m)

log-likelihood of intercept-only model: logLik(update(m, . ~ 1))

although the latter can probably be retrieved without refitting the model if we think carefully enough about the deviance() and $null.deviance components (these are defined with respect to the saturated model)