plot.semsfa {semsfa}

Default SEMSFA plotting

Description

This function plots the semiparametric/nonparametric intermediate model object estimated in the first step of the algorithm and, if efficiencies.semsfa() is esecuted, individual point estimate of the efficiency.

Usage

## S3 method for class 'semsfa'
plot(x, g.type, mod, ...)

Arguments

x

a semsfa object as returned from semsfa() or efficiencies.semsfa()

g.type

a character string indicating the type of plot. Possible values are: "reg" to plot the semiparametric/nonparametric model object estimated in the first step from semsfa(), "eff" to draw point estimate of the efficiency obtained from efficiencies.semsfa()

mod

a character string indicating the plot style for g.type="eff": "hist" for histogram and "dens" for density plot

...

further arguments passed to plot.default.

Value

The function simply generates plots.

Author(s)

Giancarlo Ferrara and Francesco Vidoli

See Also

semsfa, efficiencies.semsfa.

Examples

set.seed(0)
n<-200

#generate data
x<- runif(n, 1, 2)
fy<- 2+30*x-5*x^2
v<- rnorm(n, 0, 1)
u<- abs(rnorm(n,0,2.5))
#production frontier
y <- fy + v - u
dati<-data.frame(y,x)

#first-step: gam, second-step: fan (default)
o<-semsfa(y~s(x),dati,sem.method="gam")
#the following plot will be like that generated by plot.gam
plot(o,g.type="reg")

#adding a covariate
z<- runif(n, 1, 2)
dati$z<-z

#first-step: kernel, second-step: fan (default)
o<-semsfa(y~x+z,dati,sem.method="kernel")
#the plot will be like that generated by a plot.npreg
## Not run: plot(o,g.type="reg")

#calculate efficiencies ...
a<-efficiencies.semsfa(o)
plot(a,g.type="eff",mod="dens")

#adding further parameters as for plot.default: col, main, xlim, ...
plot(a,g.type="eff",mod="dens",col=2,main="Density Efficiency",xlim=c(0,1),xlab="Efficiency")