Convert radiation pattern from u/v form to phi/theta form

`pat_phitheta = uv2phithetapat(pat_uv,u,v)`

`pat_phitheta = uv2phithetapat(pat_uv,u,v,phi,theta)`

```
[pat_phitheta,phi_pat,theta_pat]
= uv2phithetapat(___)
```

expresses
the antenna radiation pattern `pat_phitheta`

= uv2phithetapat(`pat_uv`

,`u`

,`v`

)`pat_phitheta`

in φ/θ
angle coordinates instead of u/v space coordinates. `pat_uv`

samples
the pattern at *u* angles in `u`

and *v* angles
in `v`

. The `pat_phitheta`

matrix
uses a default grid that covers φ values from 0 to 360 degrees
and θ values from 0 to 90 degrees. In this grid, `pat_phitheta`

is
uniformly sampled with a step size of 1 for φ and θ. The
function interpolates to estimate the response of the antenna at a
given direction.

`[`

returns vectors containing the φ and θ angles at which
`pat_phitheta`

,`phi_pat`

,`theta_pat`

]
= uv2phithetapat(___)`pat_phitheta`

samples the pattern, using any of the input
arguments in the previous syntaxes.