| oc | Optimal Classification Roll Call Scaling |
| plot.OCangles | Optimal Classification Cutting Line Angles Plot |
| plot.OCcoords | Optimal Classification Coordinate Plot |
| plot.OCcutlines | Optimal Classification Cutline Plot |
| plot.OCobject | Optimal Classification Summary Plot |
| plot.OCskree | Optimal Classification Skree Plot |
| sen90 | 90th U.S. Senate Roll Call Vote Matrix |
| sen90oc | 90th U.S. Senate Ideal Points via Optimal Classification |
| summary.OCobject | Optimal Classification Summary |
| UN | United Nations Vote Data |