matlib (version 0.9.8)

workers: Workers Data

Description

A toy data set comprised of information on workers Income in relation to other variables, used for illustrating linear and multiple regression.

Usage

data("workers")

Format

A data frame with 10 observations on the following 4 variables.

Income

income from the job, a numeric vector

Experience

number of years of experience, a numeric vector

Skill

skill level in the job, a numeric vector

Gender

a factor with levels Female Male

Examples

data(workers)
plot(Income ~ Experience, data=workers, main="Income ~ Experience", pch=20, cex=2)

# simple linear regression
reg1 <- lm(Income ~ Experience, data=workers)
abline(reg1, col="red", lwd=3)

# quadratic fit?
plot(Income ~ Experience, data=workers, main="Income ~ poly(Experience,2)", pch=20, cex=2)
reg2 <- lm(Income ~ poly(Experience,2), data=workers)
fit2 <-predict(reg2)
abline(reg1, col="red", lwd=1, lty=1)
lines(workers$Experience, fit2, col="blue", lwd=3)

# How does Income depend on a factor?
plot(Income ~ Gender, data=workers, main="Income ~ Gender")
points(workers$Gender, jitter(workers$Income), cex=2, pch=20)
means<-aggregate(workers$Income,list(workers$Gender),mean)
points(means,col="red", pch="+", cex=2)
lines(means,col="red", lwd=2)