Aug 11
Finally, in the light of the greater contribution, this website will be a part of one of the largest R websites, R-Bloggers.com after following this site for a while.
For those who are using R or interested in this great but free software, R-Bloggers.com is a must!
A sneak peek of the result of a Structural Equation Model using sem package in R.
I will present in the R User Conference in Warwick next week, is reveal first here.
The following are the codes of ‘sem’ package I used in the paper.
You may also view the code of other packages to run SEM models as well.
##-------------------------------------------------##
## Measuring Transaction Cost in Supply Chains ##
## Pairach Piboonrungroj ##
## R useR conference August 2011 ##
##-------------------------------------------------##
install.packages("sem")
library(sem)
# 1. Load data
hoteldata <- read.csv("http://dl.dropbox.com/u/46344142/useR2011/cleandata.csv")
#Input covariance matrix
data.tc.1 <- cor(hoteldata)
# Have a look at the top of the data
# to check it we import the right one
head(data.tc.1)
#Create an object contains correlation matrix of the data for fitting the model in the next step
hotel.cor <- cor(hoteldata)
# path parameter start-value
model.TC.1 <- specify.model()
TC -> TC1, gamma1, NA # measurement item
TC -> TC2, gamma2, NA
TC -> TC3, gamma3, NA
TC -> TC6, gamma6, NA
TC -> TC7, gamma7, NA
TC -> TC11, gamma11, NA
TC -> TC13, gamma13, NA
TC1 <-> TC1, e1, NA # measurement error
TC2 <-> TC2, e2, NA
TC3 <-> TC3, e3, NA
TC6 <-> TC6, e6, NA
TC7 <-> TC7, e7, NA
TC11 <-> TC11, e11, NA
TC13 <-> TC13, e13, NA
TC <-> TC, NA, 1
model.TC.1
sem.TC.1 <- sem(model.TC.1, data.tc.1, 53)
# print result (fit indices, parameters, hypothesis tests)
summary(sem.TC.1)
# standardised coefficients (loadings)
std.coef(sem.TC.1)
All conference attendees are welcome to join us for drinks at The Bar on the first floor of the Rootes Building. Beer, wine, non-alcoholic drinks and light snacks will be available for all attendees.
The evening poster reception will be held at the Panorama Suite on the second floor of the Rootes Building. Beer, wine, non-alcoholic drinks and light snacks will be available for all attendees.
The conference dinner will be held at the Panorama Suite on the second floor of the Rootes Building. Admission to the conference dinner is via ticket only.
Printed abstracts will not be provided at the conference. Links to individual abstracts are provided in the timetables above and the abstracts for all contributed talks and posters are collected together in theabstract booklet.
Please note that there are three different formats for contributed talks:
Source: The Official R users Conference 2011
PS. My abstract can be found here
Next month I will have a chance to present how I use R to conduct a structural equation model in my thesis to the expeRts. And now the tentative timetable was just released.
Similar to EurOMA, I will be the last on the first day, just before the dinner.
Here is the link for the timetable.
Pairach Piboonrungroj, PhD 