| abs_sign | Find 'absolute' ptvalue |
| as_ptvalue | ptvalue: Working with precision teaching values |
| as_ptvalue.default | ptvalue: Working with precision teaching values |
| div | Create times or div vector of class *ptvalue*. |
| invert_sign | Invert ptvalue sign |
| is_ptvalue | ptvalue: Working with precision teaching values |
| ptvalue | ptvalue: Working with precision teaching values |
| times | Create times or div vector of class *ptvalue*. |