You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: uv2xyzN.m
    path of file: ./repos/PanoBasic/CoordsTransfrom
    
    the code of the file until where you have to start completion: function [ xyz ] = uv2xyzN( uv, planeID )

    
function [ xyz ] = uv2xyzN( uv, planeID )
%UV2XYZN Convert UV expression to XYZ expression in 3D
%   change UV expression to 3-dim unit vector in 3D
%   planeID: base plane for UV, 1=XY
%   Check xyz2uvN for opposite mapping
if ~exist('planeID','var')
    planeID = 1;
end