How to extract the I and Q values from eye-diagram function into separate Variable?

I have .mat file of a signal and i get the eyediagram of that signal. when i look at the workspace its the 1x1Figure. but i need the values. How can i get it. I have attached the .mat file as well. Please assist

a = load("E:\Thesis\3 mod type\frame64APSK100.mat");
a1 = eyediagram(a.frame, 8);

Answer 1

[yanqi liu]

clc; clear all; close all
a = load("frame128APSK100.mat");
a1 = eyediagram(a.frame, 8);
a2=get(a1,'Children');
a3=get(a2(1),'Children');
[a3.XData; a3.YData]
a4=get(a2(2),'Children');
[a4.XData; a4.YData]

[john karli]

I want to save the I and Q in seperate variable like.

Could it be possible?

a1(:,:,1) = I;
a1(:,:,2) = Q;

[yanqi liu]

clc; clear all; close all
a = load("frame128APSK100.mat");
a1 = eyediagram(a.frame, 8);
a2=get(a1,'Children');
a3=get(a2(1),'Children');
as(:,:,1) = [a3.XData; a3.YData];
a4=get(a2(2),'Children');
as(:,:,2) = [a4.XData; a4.YData];
figure; plot(as(1,:,1),as(2,:,1)); title('I');
figure; plot(as(1,:,2),as(2,:,2)); title('Q');

[john karli]

I am getting the following error

Unrecognized method, property, or field 'XData' for class 'matlab.graphics.GraphicsPlaceholder'.

[yanqi liu]

sir,may be check the version of matlab, the follows is run demo

clc; clear all; close all
a1 = eyediagram(rand(1024,2), 8);

a2=get(a1,'Children');
a3=get(a2(1),'Children');
as(:,:,1) = [get(a3,'XData'); get(a3,'YData')];
a4=get(a2(2),'Children');
as(:,:,2) = [get(a4,'XData'); get(a4,'YData')];
figure; plot(as(1,:,1),as(2,:,1)); title('I');

figure; plot(as(1,:,2),as(2,:,2)); title('Q');

[john karli]

can you please tell me why figure for I sample is empty?

[john karli]

theres 0 values in

as(:,:,1 )

[yanqi liu]

sir, please use matlab m file to run, do not use web to run.

clc; clear all; close all
a1 = eyediagram(rand(1024,2), 8);
a2=get(a1,'Children');
a3=get(a2(1),'Children');
as(:,:,1) = [get(a3,'XData'); get(a3,'YData')];
a4=get(a2(2),'Children');
as(:,:,2) = [get(a4,'XData'); get(a4,'YData')];
%figure; plot(as(1,:,1),as(2,:,1)); title('I');
%figure; plot(as(1,:,2),as(2,:,2)); title('Q');
disp('---------1----------')
disp(as(:,:,1))
%disp('---------2----------')
%disp(as(:,:,2))

the command display result

---------1----------
  列 1 至 5

         0    0.1250    0.2500    0.3750    0.5000
    0.0466    0.2321    0.8748    0.4601    0.0031

[john karli]

I have attached the .mat file, but here the I data contain 0 value.

clc; clear all; close all
a = load("E:\Thesis\SNR-dataset\db30\frame_snr30128APSK001.mat");
a1 = eyediagram(a.frame, 8);
a2=get(a1,'Children');
a3=get(a2(1),'Children');
as(:,:,1) = [get(a3,'XData'); get(a3,'YData')];
a4=get(a2(2),'Children');
as(:,:,2) = [get(a4,'XData'); get(a4,'YData')];
%figure; plot(as(1,:,1),as(2,:,1)); title('I');
%figure; plot(as(1,:,2),as(2,:,2)); title('Q');
disp('---------1----------')
disp(as(:,:,1))
%disp('---------2----------')
%disp(as(:,:,2))

[yanqi liu]

sir，this is my run result

the data is

[john karli]

Have you load .mat file which i uploaded?

[yanqi liu]

yes，use the

• frame_snr30128APSK001.mat

please check the

• alldata.mat

[john karli]

Thanks alot problem as in my .mat file

[john karli]

Hellow Liu

Pleae see the attached photo i am facing issue again.

[yanqi liu]

yes，sir，please use the follow：

（1）create *.m file，do not use *.mlx

（2）run the code, and do not close figure

then，watch the data

[john karli]

i do it according to your instruction but problem is same. please see attach photo

[yanqi liu]

sorry,sir,i use 2019 to develop，so please use the follow in 2021

clc; clear all; close all
a = load("frame_snr30128APSK001.mat");
a1 = eyediagram(a.frame, 8);
a2=get(a1,'Children');
ind = [];
for i = 1 : numel(a2)
    if isempty(get(a2(i),'Tag'))
        ind = [ind i];
    end
end
a3=get(a2(ind(1)),'Children');
as(:,:,1) = [get(a3,'XData'); get(a3,'YData')];
a4=get(a2(ind(2)),'Children');
as(:,:,2) = [get(a4,'XData'); get(a4,'YData')];
%figure; plot(as(1,:,1),as(2,:,1)); title('I');
%figure; plot(as(1,:,2),as(2,:,2)); title('Q');
disp('---------1----------')
disp(as(:,:,1))
%disp('---------2----------')
%disp(as(:,:,2))

[john karli]

it works. Can you please tell me what was the problem acctully?

[yanqi liu]

because in 2021 version，it trait legend as a graphic handle，so can not get the data

but in 2019 version，not appear this status

[john karli]

Thanks alot sir, As you can see my attach images i have more then 10 .mat file which i need to get the I and Q saparatll then i want to dave them in seprate .mat file with specefic name how can i do it?

[john karli]

Hi Liu

I am little confused about the I data in eye-diagram. When i plot eyediagram of two different .mat file. and get the I and Q value into sepeate variable.

after watching the value of in two seperate variable. the I data is same and Q data is changing, although the eyediagram is different. My question to you is that why tha I data is not changing when there are two different .mat file

[yanqi liu]

sir,may be close the figure before display. please consider the follow code

clc; clear all; close all
as1=get_data('frame_snr304ASK002.mat');
as2=get_data('frame_snr304ASK031.mat');
close all
% now compare as1 and as2

function as=get_data(mat_file)
close all;
a = load(mat_file);
a1 = eyediagram(a.frame, 8);
a2=get(a1,'Children');
ind = [];
for i = 1 : numel(a2)
    if isempty(get(a2(i),'Tag'))
        ind = [ind i];
    end
end
a3=get(a2(ind(1)),'Children');
as(:,:,1) = [get(a3,'XData'); get(a3,'YData')];
a4=get(a2(ind(2)),'Children');
as(:,:,2) = [get(a4,'XData'); get(a4,'YData')];

%figure; plot(as(1,:,1),as(2,:,1)); title('I');
%figure; plot(as(1,:,2),as(2,:,2)); title('Q');
% disp('---------1----------')
% disp(as(:,:,1))
%disp('---------2----------')
%disp(as(:,:,2))
end

[john karli]

I have use your code but i am surprice why 1st row in both as1 and as2 variable are same. I have attached the as1 abd as2 file please have a look

as1=get_data('frame_snr30128APSK5091.mat');
as2=get_data('frame_snr30128APSK9980.mat');

[yanqi liu]

yes，sir，the first row is X in figure Axes，at the same plot status，so them must be equal

[john karli]

isn't the first rows are in phase quadrature?

[yanqi liu]

yes，sir，i think the first row may be the xtick vector for phase quadrature