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rdummy-variable

Creating dummy variables for more than 2 levels

How do I create dummy variables for more than two levels for categorical data in r? I tried model.matrix but it didn’t work.

Solution

  • Read your coulmn as class factor.

    Suppose your data is stored in df and categories has the categories you want to convert to dummies. Then:

    df$categories <- as.factor(df$categories)

    You will not see new columns created. The factor class is a shortcut for this kind of task. Try running a regression model like this and you'll see the results.