Number of Observations

Returns the number of observations for statistical models, estimated by Maximum Likelihood using maxLik.

# S3 method for class 'maxLik'
nObs(x, ...)

Arguments

x

a statistical model estimated by Maximum Likelihood using maxLik.

...

further arguments (currently ignored).

Details

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.

Value

numeric, number of observations

Author

Arne Henningsen, Ott Toomet

See also

nObs, maxLik, nParam.

Examples

## 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 )
#> [1] 100