| exact | Make vary play exact time requested |
| seed | Set the random number seed for vary (default=0) |
| vquick | Set the value for cutrate: the number of points along the polynomial to be sampled |
| when looking for the polynomial's maximum value | |
| range | Set amplitude range: either the default: (0,4095), or (-4096,4095) |
In general, you should never have to set these.