<?xml version="1.0"?> 
<param xml:id='mex_theta'>  
  <get> 
    <amdaParam name='mex_xyz_mso'/>  
  </get> 
  <process>atan2f(sqrt($mex_xyz_mso[1]*$mex_xyz_mso[1]+$mex_xyz_mso[2]*$mex_xyz_mso[2]),($mex_xyz_mso[0]-0.55))</process> 
  <output/> 
</param>