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_u.m
    path of file: ./repos/malini/Codes/deconvolution - model/spm8
    
    the code of the file until where you have to start completion: function [u] = spm_u(a,df,STAT)
% uncorrected critical height threshold at a specified significance level
% FORMAT [u] = spm_u(a,df,STAT)
% a     - critical probability - {alpha}
% df    - [df{interest} df{error}]
% STAT  - Statistical field
%               'Z' - Gaussian field
%               'T' - T - field
%               'X' - Chi squared field
%               'F' - F - field
%               'P' - P - value
%
% u     - critical height {uncorrected}
%__________________________________________________________________________
%
% spm_u returns the uncorrected critical threshold at a specified 
% significance
%__________________________________________________________________________
% Copyright (C) 2008 Wellcome Trust Centre for Neuroimaging

% Karl Friston
% $Id: spm_u.m 2690 2009-02-04 21:44:28Z guillaume $


if     STAT == 'Z'

    u   = spm_invNcdf(1 - a      );

elseif STAT == 'T'

    
function [u] = spm_u(a,df,STAT)
% uncorrected critical height threshold at a specified significance level
% FORMAT [u] = spm_u(a,df,STAT)
% a     - critical probability - {alpha}
% df    - [df{interest} df{error}]
% STAT  - Statistical field
%               'Z' - Gaussian field
%               'T' - T - field
%               'X' - Chi squared field
%               'F' - F - field
%               'P' - P - value
%
% u     - critical height {uncorrected}
%__________________________________________________________________________
%
% spm_u returns the uncorrected critical threshold at a specified 
% significance
%__________________________________________________________________________
% Copyright (C) 2008 Wellcome Trust Centre for Neuroimaging

% Karl Friston
% $Id: spm_u.m 2690 2009-02-04 21:44:28Z guillaume $


if     STAT == 'Z'

    u   = spm_invNcdf(1 - a      );

elseif STAT == 'T'

    u   = spm_invTcdf(1 - a,df(2));

elseif STAT == 'X'

    u   = spm_invXcdf(1 - a,df(2));

elseif STAT == 'F'

    u   = spm_invFcdf(1 - a,df   );

elseif STAT == 'P'

    u   = a;

end