# questions on descarte planning, meaning of orient_increment

Hey all,

I wonder what is the meaning of ** orient_increment** in

**? On its class reference, it shows**

*AxialSymmetricPt*```
> orient_increment (in radians, discretization of space [-Pi, Pi])
```

But what does discretization mean here? My understanding is that it discretize [-Pi,Pi], like [-pi, -pi+0.01,-pi+0.02,....,pi-0.01,pi]. Is this right?

I was following the descarte tutorial, it used this helper function

```
descartes_core::TrajectoryPtPtr makeTolerancedCartesianPoint(const Eigen::Affine3d& pose)
{
using namespace descartes_core;
using namespace descartes_trajectory;
return TrajectoryPtPtr( new AxialSymmetricPt(pose, // Nominal pose
M_PI/2.0, // Search discretization
AxialSymmetricPt::Z_AXIS) ); // Free axis
}
```

I wonder what does the M_PI/2 means.

Any help would be deeply appreciated.