Create dummy variable to do two-way ANOVA

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d = data.frame(
    Temperature = c(rep("Cool", 6), rep("Warm", 6)),
    Bact = c(rep("Bact 1", 2), rep("Bact 2", 2), rep("Bact 3", 2), rep("Bact 1", 2), rep("Bact 2", 2), rep("Bact 3", 2)),
    Time = c(15.23,14.32,14.77,15.12,14.05,15.48,14.13,16.13,16.44,14.82,17.96,16.65)
)

I self-created a small data frame for a two-way ANOVA. I want to test a two-way ANOVA by

summary(aov(Time~Bact*Temperature, data=d))

Time is the dependent variable while Bact and Temperature are two categorical independent variables.

My goal is to learn and prove ANOVA can be done with a linear regression model. I want to convert convert my data into dummy variable and perform a linear regression on it. I expect I'll recover the same results.

The problem is that, I don't know how to convert my data frame into dummy variables such that it can be used in the lm() function.

asked 29 secs ago

Student T

1,932

Create dummy variable to do two-way ANOVA