expit {clusterPower} | R Documentation |
The expit and logit functions are useful shortcuts when using logistic regression models.
expit(x) logit(p)
x |
a real number |
p |
a number between 0 and 1, i.e. a probability |
The logit function is defined as logit(p) = log(p)/log(1-p) and can also be described as the log odds of a given probability. The expit is the inverse of the logit function and is defined as expit(x) = exp(x)/(1+exp(x)).
A numeric value, possibly vectorized, depending on the input.
Nicholas G. Reich
expit(-2) curve(expit(x), from=-5, to=5) logit(.5) curve(logit(x), from=0, to=1)