Categorical covariates

Hi,

I’ve got a naive question about categorical covariates when running association analysis. From the tutorial, it seems like categorical covariates have to be a boolean (isFemale true/false). Is there a way to run covariates with more than two levels, such as study site? Is there a way to get hail to see these as factors in R? Or would i have to decompose the covariates to multiple true/false columns (i.e. go from one column with site IDs to multiple columns as below)?

| sites | isSiteA | isSiteB | isSiteC |
|-------|---------|---------|---------|
| A     | true    | false   | false   |
| B     | false   | true    | false   |
| B     | false   | true    | false   |
| C     | false   | false   | true    |
| B     | false   | true    | false   |
| A     | true    | false   | false   |

Thanks,
-Jon

Don’t have this at the moment, but it’s definitely a useful functionality – maybe a way to add a one-hot encoding for a categorical variable?