R ltm()

1 개요

R ltm()

library(ltm)
df <- read.csv("https://github.com/jmnote/zdata/raw/master/github.com/drizopoulos/ltm/data/LSAT.csv")
model <- ltm(df ~ z1, IRT.param = TRUE)
coef(model)

library(ltm)
df <- read.csv("https://github.com/jmnote/zdata/raw/master/github.com/drizopoulos/ltm/data/WIRS.csv")
model <- ltm(df ~ z1, constr = rbind(c(1, 1, 1), c(6, 2, -0.5))
coef(model)

## Two-factor model with an interaction term
library(ltm)
df <- read.csv("https://github.com/jmnote/zdata/raw/master/github.com/drizopoulos/ltm/data/WIRS.csv")
model <- ltm(df ~ z1 * z2)
coef(model)

## One-factor and a quadratic term
library(ltm)
df <- read.csv("https://github.com/jmnote/zdata/raw/master/github.com/drizopoulos/ltm/data/Mobility.csv")
model <- ltm(df ~ z1 + I(z1^2))
coef(model)

## The two-parameter logistic model with 20 quadrature points and 20 EM iterations
library(ltm)
df <- read.csv("https://github.com/jmnote/zdata/raw/master/github.com/drizopoulos/ltm/data/Abortion.csv")
model <- ltm(df ~ z1, control = list(GHk = 20, iter.em = 20))
coef(model)

2 같이 보기

• R ltm

3 참고

• https://www.rdocumentation.org/packages/ltm/versions/1.1-1/topics/ltm