Computes the log-likelihood for i.i.d. exponential observations.
L(λ|x) = nlog(λ) - λΣxᵢ
Usage
loglik_exponential(rate, x)
Arguments
- rate
Rate parameter λ (value object), must be positive
- x
Numeric vector of observations (must be non-negative)
Value
A value object representing the log-likelihood
Examples
if (FALSE) { # \dontrun{
x <- rexp(50, rate = 2)
rate <- val(1)
ll <- loglik_exponential(rate, x)
backward(ll)
grad(rate) # should be n/rate - sum(x)
} # }