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: HELP_runTetGen.m
    path of file: ./repos/GIBBON/docs
    
    the code of the file until where you have to start completion: %% runTetGen
% Below is a demonstration
    
function to control local mesh density

%%
% Build example geometry
boxDim =[12 2 3];
boxEl  =[12 2 3];
[F,V,C]=quadBox(boxDim,boxEl);
V_input=V;

%% 
% Defining a size function on the boundary nodes

%Get edge lengths and base minimum size on input edge lengths
[edgeLengths]=patchEdgeLengths(F,V);
minEdgeSize=mean(edgeLengths)/5; %The smallest element size

n=5; %The largest element edge length is n times minEdgeSize
edgeSizeField=V(:,1);
edgeSizeField=edgeSizeField-min(edgeSizeField(:));
edgeSizeField=edgeSizeField./max(edgeSizeField(:));
edgeSizeField=(edgeSizeField*(n-1))+1; %Range from 0-n depend