MATLAB: Using the time length of the audio signal as a time axis

MATLAB

How can i create a time axis, which is as long as my audio signal? I want to create a 3D-Plot, but i need to know, how to define my time axis.
I can get the length of my time axis, by putting the code line in my command window like this:
[y,fs] = audioread('filename');
TotalTime = length(y)./fs;
TotalTime
(for example) 10.8566*
Sorry if the questions sounds silly, but how can i write this? Doing it in matlab, btw. bold

Best Answer

[y,fs] = audioread('filename');
t = linspace(0,length(y)/fs,length(y)) ;