Help for package RegKink (original) (raw)

Type: Package
Version: 0.1.0
Title: Regression Kink with a Time-Varying Threshold
Description: An algorithm is proposed to estimate regression kink model proposed by the paper, Lixiong Yang and Jen-Je Su (2018) <doi:10.1016/j.jimonfin.2018.06.002>.
Imports: MASS
Depends: R (≥ 3.5.0)
License: GPL-2 | GPL-3 [expanded from: GPL]
Encoding: UTF-8
RoxygenNote: 7.1.1
Author: Lixiong Yang [aut, cre]
Maintainer: Lixiong Yang ylx@lzu.edu.cn
NeedsCompilation: no
Packaged: 2021-04-13 07:58:25 UTC; ylx
Repository: CRAN
Date/Publication: 2021-04-15 07:30:06 UTC

negtive part of a variable

Description

This is a function computing the negtive part of a variable.

Usage

neg.part(x)

Arguments

Value

ne The negative part of a variable.

Examples


pt1 <- proc.time()
##Simulated data
set.seed(12345)
n=200
x = rnorm(n)
obj <- neg.part(x)

proc.time() - pt1

positive part of a variable

Description

This is a function computing the positive part of a variable.

Usage

pos.part(x)

Arguments

Value

ps The positive part of a variable.

Examples


pt1 <- proc.time()
##Simulated data
set.seed(12345)
n=200
x = rnorm(n)
obj <- pos.part(x)

proc.time() - pt1

linear regression

Description

This is a function computing OLS estimates of linear model.

Usage

reg(X,y)

Arguments

y A vector of response.
X data matrix

Value

bols The ols estimates of a linear regression model.

Examples


pt1 <- proc.time()
##Simulated data
set.seed(12345)
n=200
e = rnorm(n)
X = cbind(1,rnorm(n))
b0 =c(1,2)
y = X
obj <- reg(X,y)

proc.time() - pt1

Estimation for regression kink with a time-varying threshold

Description

This is a function estimating regression kink with a time-varying threshold.

Usage

rkt(y,x,z,q,r01,r02,r11,r12,stp1,stp2)

Arguments

y A vector of response.
x A vector of regressor
z A data matrix of control variables
q A vector of variable affecting threshold
r01 Lower bounder of parameter space for r0
r02 Upper bounder of parameter space for r0
r11 Lower bounder of parameter space for r1
r12 Upper bounder of parameter space for r1
stp1 Step used in grid search of r0
stp2 Step used in grid search of r1

Value

A list with the elements

bols The OLS estimates when a kink effect is ignored.
bt The regression coefficients when a kink effect is included in the model.
gammahat0 The estimated threshold of the constant one in threshold parameters.
gammahat1 The estimated threshold of the slop in threshold parameters.
sig The sum of squred errors of the kink model.

Examples


sta <- proc.time()
##Simulated data
set.seed(12345)
n=200
x = rnorm(n)
q = rnorm(n)
rt = 0.2 - 0.5*q
z = rnorm(n)
x1 = cbind(neg.part(x-rt),pos.part(x-rt),z)
b0 =c(1,2,1)
y = b0[1]*x1[,1]+b0[2]*x1[,2]+b0[3]*x1[,3]+ rnorm(n)


# set grid search paramaters
r01 = 0
r02 = 2
stp1 = 0.1
r11 = -10
r12 = 5
stp2 = 0.1
# estimate the model with a state-dependent threshold
est1 <- rkt(y,x,z,q,r01,r02,r11,r12,stp1,stp2)

proc.time() - sta