npsf (version 0.8.0)

nobs.npsf: 'nobs' method for class 'npsf'

Description

Extracts the number of observations for which efficiencies are estimated by SF or DEA model estimated by sf, teradial, tenonradial, or teradialbc.

Usage

# S3 method for npsf
nobs( object, … )

Arguments

object

an object of class npsf returned by the function sf).

…

currently unused.

Value

nobs.npsf returns the number of observations for which efficiencies are estimated by SF or DEA model.

See Also

vcov.npsf, coef.npsf, summary.npsf, and sf.

Examples

# NOT RUN {
require( npsf )
 
# Load Penn World Tables 5.6 dataset
 
data( pwt56 )
head( pwt56 )
 
# Create some missing values
 
pwt56 [4, "K"] <- NA 
 
# Stochastic production frontier model with 
# homoskedastic error components (half-normal)
 
# Use subset of observations - for year 1965
 
m1 <- sf(log(Y) ~ log(L) + log(K), data = pwt56, 
 subset = year == 1965, distribution = "h")
nobs( m1 )

# DEA

t1 <- teradialbc ( Y ~ K + L, data = pwt56, subset = Nu < 10)
nobs(t1)
# }