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: xASL_stat_fcdf.m
    path of file: ./repos/ExploreASL/Functions/Statistics
    
    the code of the file until where you have to start completion: function p = xASL_stat_fcdf(F,M,N)
% F distribution function.
%
% FORMAT: F = xASL_stat_fcdf(F,M,N)
%
% INPUT:
%   F        - F-value for which the CDF is calculated
%   M,N      - Degrees of freedom of the CDF, either scalar or same size as T
%
% OUTPUT:
%   p        - Value of the CDF
%
% -----------------------------------------------------------------------------------------------------------------------------------------------------
% DESCRIPTION: Calculates the cumulative distribution function of the F-distribution for degrees of freedom M,N at value F.
%
% EXAMPLE: p = xASL_stat_fcdf(F,M,N)
%
% -----------------------------------------------------------------------------------------------------------------------------------------------------
% REFERENCES: C. Walck. Hand-book on STATISTICAL DISTRIBUTIONS for experimentalists. 1996. University of Stockholm. 
%             http://inspirehep.net/record/1389910/files/suf9601.pdf
% __________________________________

    
function p = xASL_stat_fcdf(F,M,N)
% F distribution function.
%
% FORMAT: F = xASL_stat_fcdf(F,M,N)
%
% INPUT:
%   F        - F-value for which the CDF is calculated
%   M,N      - Degrees of freedom of the CDF, either scalar or same size as T
%
% OUTPUT:
%   p        - Value of the CDF
%
% -----------------------------------------------------------------------------------------------------------------------------------------------------
% DESCRIPTION: Calculates the cumulative distribution function of the F-distribution for degrees of freedom M,N at value F.
%
% EXAMPLE: p = xASL_stat_fcdf(F,M,N)
%
% -----------------------------------------------------------------------------------------------------------------------------------------------------
% REFERENCES: C. Walck. Hand-book on STATISTICAL DISTRIBUTIONS for experimentalists. 1996. University of Stockholm. 
%             http://inspirehep.net/record/1389910/files/suf9601.pdf
% __________________________________
% Copyright (C) 2015-2019 ExploreASL

% If degrees of freedom are given as a scalar value
if nargin < 3 || isempty(M) || isempty(N) || isempty(F)
	error('Need three input parameters.');
end