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: pr_spm_hrf.m
    path of file: ./repos/malini/Codes/deconvolution - model/spm8/marsbar-0.44/@mardo_99/private
    
    the code of the file until where you have to start completion: function [hrf,p] = pr_spm_hrf(RT,P);
% returns a hemodynamic response function

    
function [hrf,p] = pr_spm_hrf(RT,P);
% returns a hemodynamic response function
% FORMAT [hrf,p] = pr_spm_hrf(RT,[p]);
% RT   - scan repeat time
% p    - parameters of the response function (two gamma functions)
%
%							defaults
%							(seconds)
%	p(1) - delay of response (relative to onset)	   6
%	p(2) - delay of undershoot (relative to onset)    16
%	p(3) - dispersion of response			   1
%	p(4) - dispersion of undershoot			   1
%	p(5) - ratio of response to undershoot		   6
%	p(6) - onset (seconds)				   0
%	p(7) - length of kernel (seconds)		  32
%
% hrf  - hemodynamic response function
% p    - parameters of the response function
%_______________________________________________________________________
% @(#)spm_hrf.m	2.7 Karl Friston 99/05/17

% global parameter
%-----------------------------------------------------------------------
global fMRI_T; 
if isempty(fMRI_T), fMRI_T = 16; end