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: gamm_pdf.m
    path of file: ./repos/malini/Codes/FC_EC_calculation code/DynamicFC/jplv7/distrib
    
    the code of the file until where you have to start completion: function f = gamm_pdf (x, a)
% PURPOSE: returns the pdf at x of the gamma(a) distribution
%---------------------------------------------------
% USAGE: pdf = gamm_pdf(x,a)
% where: x = a vector  
%        a = a scalar for gamma(a)
%---------------------------------------------------
% RETURNS:
%        a vector of pdf at each element of x of the gamma(a) distribution      
% --------------------------------------------------
% SEE ALSO: gamm_cdf, gamm_rnd, gamm_inv
%---------------------------------------------------

%       Anders Holtsberg, 18-11-93

    
function f = gamm_pdf (x, a)
% PURPOSE: returns the pdf at x of the gamma(a) distribution
%---------------------------------------------------
% USAGE: pdf = gamm_pdf(x,a)
% where: x = a vector  
%        a = a scalar for gamma(a)
%---------------------------------------------------
% RETURNS:
%        a vector of pdf at each element of x of the gamma(a) distribution      
% --------------------------------------------------
% SEE ALSO: gamm_cdf, gamm_rnd, gamm_inv
%---------------------------------------------------

%       Anders Holtsberg, 18-11-93
%       Copyright (c) Anders Holtsberg

if nargin ~= 2
error('Wrong # of arguments to gamm_cdf');
end