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: covPERard.m
    path of file: ./repos/hctsa/Toolboxes/gpml/cov
    
    the code of the file until where you have to start completion: function K = covPERard(cov, hyp,
    
function is parameterized as:
%
% k(x,z) = k0(u(x),u(z)), u(x) = [sin(pi*x/p); cos(pi*x/p)]
%
% where the period p belongs to covPERiso and hyp0 belong to k0:
%
% hyp = [ log(p_1)
%         log(p_2)
%          .
%         log(p_D)
%         hyp0 ]
%
% The first D hyperparameters of k0 are the log lengthscales such that
% hyp0(i) = log(ell(i)) for i=1..D.
% Note that for k0 = covSEard and D = 1, a faster alternative is covPeriodic.
%
% Copyright (c) by Hannes Nickisch, 2013-10-16.
%
% See also COVFUNCTIONS.M.

nocov = false;                   % default case when no cov argument is provided
if nargin==0, cov = {@covSEard}; nocov = true; end