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: spm_get_vc.m
    path of file: ./repos/ExploreASL/External/SPMmodified
    
    the code of the file until where you have to start completion: function Vi = spm_get_vc(I,factor)
% Generate error covariance components for factorial designs

    
function Vi = spm_get_vc(I,factor)
% Generate error covariance components for factorial designs
% FORMAT Vi = spm_get_vc(I,factor)
% I         - n x m matrix of factor level indicators
%             I(n,i) is the level of factor i for observation n
% factor(i) - structure array of sphericity assumptions for each factor
% .variance - 1 for different variance among levels of factor i
% .dept     - 1 for depend