I have a time-domain signal generated from Cadence Virtuoso at the receiver side. I can plot eye diagram in Virtuoso. But having problem to generate eye diagram from the signal. my y data is a vector. I simply used the following code:

    fid = fopen('Data.csv');

    readData = textscan(fid,'%f %f','Headerlines',1,'Delimiter',',');

    % Extract data from readData
    xData = readData{1,1}(:,1);
    yData = readData{1,2}(:,1);

    eyediagram(yData,300,10e-10);

But the eye diagram is not the same that I generated in Virtuoso. The toal time signal is 30ns total and I used 500ps as period for generating eye diagram in Virtuoso. My #Matlab code generates eye diagram but the overall superimposed eyes shape looks shifted. Can any expert help me about this issue to generate it?