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: demgtm1.m
    path of file: ./repos/pcm/matlab/lib/netlab3_3
    
    the code of the file until where you have to start completion: %DEMGTM1 Demonstrate EM for GTM.
%
%	Description
%	 This script demonstrates the use of the EM algorithm to fit a one-
%	dimensional GTM to a two-dimensional set of data using maximum
%	likelihood. The location and spread of the Gaussian kernels in the
%	data space is shown during training.
%
%	See also
%	DEMGTM2, GTM, GTMEM, GTMPOST
%

%	Copyright (c) Ian T Nabney (1996-2001)

% Demonstrates the GTM with a 2D target space and a 1D latent space.
%
%		This script generates a simple data set in 2 dimensions, 
%		with an intrinsic dimensionality of 
    
function (y = x + 1.25*sin(2*x))\n', ...
'\nPress any key to continue ...\n\n']);
pause;

% Generate a unit circle figure, to be used for plotting
src = [0:(2*pi)/(20-1):2*pi]';
unitC = [sin(src) cos(src)];

% Generate and plot (along with the data) an initial GTM model

clc;
num_latent_points = 20;
num_rbf_centres = 5;

net = gtm(1, num_latent_points, 2, num_rbf_centres, 'gaussian');

options = foptions;;
options(7) = 1;
net = gtminit(net, options, T, 'regular', num_latent_points, ...
   num_rbf_centres);

mix = gtmfwd(net);
% Replot the figure
hold off;
plot(mix.centres(:,1),  mix.centres(:,2), 'g');
hold on;
for i=1:num_latent_points
  c = 2*unitC*sqrt(mix.covars(1)) + [ones(20,1)*mix.centres(i,1) ...
      ones(num_latent_points,1)*mix.centres(i,2)];
  fill(c(:,1), c(:,2), [0.8 1 0.8]);
end