nobs.npsf {npsf} | R Documentation |
Extracts the number of observations for which efficiencies are estimated
by SF or DEA model estimated by sf
, teradial
,
tenonradial
, or teradialbc
.
## S3 method for class 'npsf'
nobs( object, ... )
object |
an object of class |
... |
currently unused. |
nobs.npsf
returns the number of observations for which efficiencies are estimated by SF or DEA model.
Oleg Badunenko <oleg.badunenko@brunel.ac.uk>
vcov.npsf
, coef.npsf
, summary.npsf
, and sf
.
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)