Sometimes we need to run a regression analysis on a subset or sub-sample. That’s quite simple to do in R. All we need is the `subset`

command. Let’s look at a linear regression:

`lm(y ~ x + z, data=myData)`

Rather than run the regression on all of the data, let’s do it for only women, or only people with a certain characteristic:

`lm(y ~ x + z, data=subset(myData, sex=="female"))`

`lm(y ~ x + z, data=subset(myData, age > 30))`

The `subset()`

command identifies the data set, and a condition how to identify the subset.