Create contour for eyediagram

Hello,

I would like to create the contour plot for an eyediagram and measure its height and width.

Here i use the code from https://stackoverflow.com/questions/29165412/matlab-to-python-code-conversion-output-isnot-matching to generate the eyediagram, however, how do I get the contour plot as shown in the figure (the red curve) and measure its height and width?

Thanks a lot

clear

N = 10^3; % number of symbols

am = 2*(rand(1,N)>0.5)-1 + j*(2*(rand(1,N)>0.5)-1); % generating random binary sequence

fs = 10; % sampling frequency in Hz

% defining the sinc filter

sincNum = sin(pi*[-fs:1/fs:fs]); % numerator of the sinc function

sincDen = (pi*[-fs:1/fs:fs]); % denominator of the sinc function

sincDenZero = find(abs(sincDen) < 10^-10);

sincOp = sincNum./sincDen;

sincOp(sincDenZero) = 1; % sin(pix/(pix) =1 for x =0

% raised cosine filter

alpha = 0.5;

cosNum = cos(alpha*pi*[-fs:1/fs:fs]);

cosDen = (1-(2*alpha*[-fs:1/fs:fs]).^2);

cosDenZero = find(abs(cosDen)<10^-10);

cosOp = cosNum./cosDen;

cosOp(cosDenZero) = pi/4;

gt_alpha5 = sincOp.*cosOp;

alpha = 1;

cosNum = cos(alpha*pi*[-fs:1/fs:fs]);

cosDen = (1-(2*alpha*[-fs:1/fs:fs]).^2);

cosDenZero = find(abs(cosDen)<10^-10);

cosOp = cosNum./cosDen;

cosOp(cosDenZero) = pi/4;

gt_alpha1 = sincOp.*cosOp;

% upsampling the transmit sequence

amUpSampled = [am;zeros(fs-1,length(am))];

amU = amUpSampled(:).';

% filtered sequence

st_alpha5 = conv(amU,gt_alpha5);

st_alpha1 = conv(amU,gt_alpha1);

% taking only the first 10000 samples

st_alpha5 = st_alpha5([1:10000]);

st_alpha1 = st_alpha1([1:10000]);

st_alpha5_reshape = reshape(st_alpha5,fs*2,N*fs/20).';

st_alpha1_reshape = reshape(st_alpha1,fs*2,N*fs/20).';

close all

figure;

st_alpha5_reshape

plot(real(st_alpha5_reshape(10:end-10,:)).','b');

title('eye diagram with alpha=0.5');

xlabel('time')

ylabel('amplitude')

axis([0 2 -1.5 1.5])

grid on

figure;

plot([0:1/fs:1.99],real(st_alpha1_reshape).','b');

title('eye diagram with alpha=1')

xlabel('time')

ylabel('amplitude')

axis([0 2 -1.5 1.5 ])

grid on