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: initFactor.m
    path of file: ./repos/MatlabFunc/SLEP
    
    the code of the file until where you have to start completion: function ratio=initFactor(x_norm, Ax , y, z, funName, rsL2, x_2norm)
% 
%% function initFactor
%     compute the an optimal constant factor for the initialization
%
%
% Input parameters:
% x_norm-      the norm of the starting point
% Ax-          A*x, with x being the initialization point

    
function ratio=initFactor(x_norm, Ax , y, z, funName, rsL2, x_2norm)
% 
%% function initFactor
%     compute the an optimal constant factor for the initialization
%
%
% Input parameters:
% x_norm-      the norm of the starting point
% Ax-          A*x, with x being the initialization point
% y-           the response matrix
% z-           the regularization parameter or the ball
% funName-     the name of the function
%
% Output parameter:
% ratio-       the computed optimal initialization point is ratio*x
%
%% Copyright (C) 2009-2010 Jun Liu, and Jieping Ye
%
% For any problem, please contact with Jun Liu via j.liu@asu.edu
%
% Last revised on August 2, 2009.

switch(funName)
    case 'LeastC'
        ratio_max     = z / x_norm;
        ratio_optimal = Ax'*y / (Ax'*Ax + rsL2 * x_2norm);
        
        if abs(ratio_optimal)<=ratio_max
            ratio  =  ratio_optimal;
        elseif ratio_optimal<0
            ratio  =  -ratio_max;
        else
            ratio  =  ratio_max;
        end