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: CBIG_olda_SplitWCIntoObsUnObs.m
    path of file: ./repos/CBIG/utilities/matlab/HBM/onlinelda
    
    the code of the file until where you have to start completion: function [obs_wc, unobs_wc] = CBIG_SplitWCIntoObsUnObs(wc, frac_obs)

% Split words into observed and unobserved
% FORMAT [obs_wc, unobs_wc] = SplitWCIntoObsUnObs(wc, frac_obs)
%
% wc       = 1 x V vector, where wc(i) = # times ith vocab word appears
% frac_obs = fraction of words that are deemed observable
%
% obs_wc   = observed words

    
function [obs_wc, unobs_wc] = CBIG_SplitWCIntoObsUnObs(wc, frac_obs)

% Split words into observed and unobserved
% FORMAT [obs_wc, unobs_wc] = SplitWCIntoObsUnObs(wc, frac_obs)
%
% wc       = 1 x V vector, where wc(i) = # times ith vocab word appears
% frac_obs = fraction of words that are deemed observable
%
% obs_wc   = observed words
% unobs_wc = unobservved words 
%
% Written by B.T.Thomas Yeo and CBIG under MIT licence: https://github.com/ThomasYeoLab/CBIG/blob/master/LICENSE.md

if size(wc,1) ~= 1
    error('Input argument ''wc'' should be a row vector');
end