Returns the number of observations for statistical models,
estimated by Maximum Likelihood using maxLik.
# S3 method for maxLik
nObs(x, ...)numeric, number of observations
a statistical model estimated by Maximum Likelihood
using maxLik.
further arguments (currently ignored).
Arne Henningsen, Ott Toomet
The nObs method for “maxLik” objects
can return the number of observations only if log-likelihood function
(or the gradient) returns values by individual observation.
nObs, maxLik,
nParam.
## fit a normal distribution by ML
# generate a variable from normally distributed random numbers
x <- rnorm( 100, 1, 2 )
# log likelihood function (for individual observations)
llf <- function( param ) {
return( dnorm( x, mean = param[ 1 ], sd = param[ 2 ], log = TRUE ) )
}
## ML method
ml <- maxLik( llf, start = c( mu = 0, sigma = 1 ) )
# return number of onservations
nObs( ml )
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