#5710 Lab - Week of 3/9

#Import Ginzberg data set, or if you have Rcmdr running, Ginzberg is already available
library(Rcmdr)

#1 Regression with simplicity and fatalism predicting depression
LinearModel.1 <- lm(depression ~ simplicity  + fatalism , data=Ginzberg)
summary(LinearModel.1)

#2 Regression with simplicity, fatalism, and interaction predicting depression
LinearModel.2 <- lm(depression ~ simplicity + fatalism + simplicity :fatalism , data=Ginzberg)
summary(LinearModel.2)

#3 Make Ginzberg the active dataset (may do so through Data/Data in packages/Read data/car) and plot the interaction via Rcmdr menu (several packages are required which it will load automatically).
#4 Another plot of the interaction.  Note that 'all.effects' is allEffects in more recent versions of R.
attach(Ginzberg)
plot(all.effects(LinearModel.2, xlevels=list(fatalism =seq(0,2,by=.5), simplicity = seq(0,3,by=.1) )), ask = F, multiline = T, colors = rainbow (10), key.args = list (x=0.05, y = 0.7, corner = c(0,0)))

#5 Compare models
anova(LinearModel.1,LinearModel.2)

#Import Attitude data set
attitude <- read.table("http://www.unt.edu/rss/class/mike/data/sobeldataset.dat", header=TRUE, sep="", na.strings="NA", dec=".", strip.white=TRUE)

#11 Test mediation 
attach(attitude)
library(multilevel)
sobel(Attitude, Intention, Behavior)