data(byssinosis)| [,1] | dust |
| Factor w/ 3 levels "most","less" | [,2] |
| race | Factor w/ 2 levels "white","non-white" |
| [,3] | sex |
| Factor w/ 2 levels "male","female" | [,4] |
| smok | Factor w/ 2 levels "smoker","non" |
| [,5] | emp |
| Factor w/ 3 levels "<10","10-20",...< td=""> | [,6] | 10","10-20",...<>
| yes | int, Number of workers who suffered byssinosis |