function [y,t,n_std]=hw2_generate_Y(example);



if example == 1
	% Generate true signal
	t=[1:50]';
	N=length(t);
	% Generate Gaussian Random Noise with zero mean and variance=9.
	n_std=3;
	n = bs_rand('norm', [0, 1 ], N, 1);
	n = n-mean(n); n = n_std*n/std(n);
	y=1+2*t+n;
end


if example == 2
	% Generate true signal
	t=[1:50]';
	N=length(t);
	% Generate Gaussian Random Noise with zero mean and variance=9.
	n_std=30;
	n = bs_rand('norm', [0, 1 ], N, 1);
	n = n-mean(n); n = n_std*n/std(n);
	y=1+2*t+n;
end

if example == 3
	% Generate true signal
	t=[1:20]';
	n_std=30;
	N=length(t);
	% Generate Gaussian Random Noise with zero mean and variance=9.
	n = bs_rand('norm', [0, 1 ], N, 1);
	n = n-mean(n); n = n_std*n/std(n);
	y=1 + 2*t.^2 + n;
end

if example == 4
	% Generate true signal
	t=[1:50]';
	n_std=30;
	N=length(t);
	% Generate Gaussian Random Noise with zero mean and variance=9.
	n = bs_rand('norm', [0, 1 ], N, 1);
	n = n-mean(n); n = n_std*n/std(n);
	y=1 + 2*t.^2 + n;
end

if example == 5
	% Upload Keeling Curve
	load CO2.mat
	t=[1:length(co2)]';
	y=co2(~isnan(co2));
	t=t(~isnan(co2));	
	n_std=1;
	N=length(t);
end