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_Tcdf.m
    path of file: ./repos/PsPM/src/ext/VBA/stats&plots/spm_code
    
    the code of the file until where you have to start completion: function F = spm_Tcdf(x,v)
% Cumulative Distribution Function (CDF) of Students t distribution
% FORMAT p = spm_Tcdf(x,v)
%
% x - T-variate (Student's t has range (-Inf,Inf)
% v - degrees of freedom (v>0, non-integer d.f. accepted)
% F - CDF of Student's t-distribution with v degrees of freedom at points x

    
function F = spm_Tcdf(x,v)
% Cumulative Distribution Function (CDF) of Students t distribution
% FORMAT p = spm_Tcdf(x,v)
%
% x - T-variate (Student's t has range (-Inf,Inf)
% v - degrees of freedom (v>0, non-integer d.f. accepted)
% F - CDF of Student's t-distribution with v degrees of freedom at points x
%__________________________________________________________________________
%
% spm_Tcdf implements the Cumulative Distribution of the Students t-distribution.
%
% Definition:
%--------------------------------------------------------------------------
% The CDF F(x) of the Student's t-distribution with v degrees of
% freedom is the probability that a realisation of a t random variable
% X has value less than x; F(x)=Pr{X<x} for X~G(h,c). Student's
% t-distribution is defined for real x and positive integer v (See
% Evans et al., Ch37).
%
% This implementation is not restricted to whole (positive integer) df
% v, rather it will compute for any df v>0.
%
% Variate relationships: (Evans et al., Ch37 & 7)
%--------------------------------------------------------------------------
% The Student's t distribution with 1 degree of freedom is the Standard
% Cauchy distribution, which has a simple closed form CDF.
%
% Algorithm:
%--------------------------------------------------------------------------
% The CDF of the Student's t-distribution with v degrees of freedom
% is related to the incomplete beta function by:
%       Pr(|X|<x) = betainc(v/(v+x^2),v/2,1/2)
% so
%              {     betainc(v/(v+x^2),v/2,1/2) / 2      for x<0
%       F(x) = |   0.5                                   for x=0
%              { 1 - betainc(v/(v+x^2),v/2,1/2) / 2      for x>0
%
% See Abramowitz & Stegun, 26.5.27 & 26.7.1; Press et al., Sec6.4 for
% definitions of the incomplete beta function. The relationship is
% easily verified by substituting for v/(v+x^2) in the integral of the
% incomplete beta function.
%
% MATLAB's implementation of the incomplete beta function is used.
%
%
% References:
%--------------------------------------------------------------------------
% Evans M, Hastings N, Peacock B (1993)
%       "Statistical Distributions"
%        2nd Ed. Wiley, New York
%
% Abramowitz M, Stegun IA, (1964)
%       "Handbook of Mathematical Functions"
%        US Government Printing Office
%
% Press WH, Teukolsky SA, Vetterling AT, Flannery BP (1992)
%       "Numerical Recipes in C"
%        Cambridge
%
%__________________________________________________________________________
% Copyright (C) 1992-2011 Wellcome Trust Centre for Neuroimaging

% Andrew Holmes
% $Id: spm_Tcdf.m 378 2016-11-07 13:17:49Z tmoser $


%-Format arguments, note & check sizes
%--------------------------------------------------------------------------
if nargin<2, error('Insufficient arguments'), end