Logit function

Logit function

Usage

logit(pi)

Arguments

pi

Numeric value on the interval \([0,1]\) (usually a probability).

Value

Numeric value, result of log(pi/(1-pi)).

See also

inv_logit()

Examples

# probabilities 
prob_ICE_base <- 0.3
prob_ICE_risk <- 0.6
# model coefficients
(beta1 <- logit(prob_ICE_base))
(beta2 <- logit(prob_ICE_risk) - logit(prob_ICE_base))
# linear predictor 
logit(prob_ICE_base); (lin_pred1 <- beta1 + beta2*0)
logit(prob_ICE_risk); (lin_pred2 <- beta1 + beta2*1)
# inverse logit of linear predictor 
(inv_logit(lin_pred1)) # prob for X1 = 0
(inv_logit(lin_pred2)) # prob for X1 = 1