How to add 0 values before and after a sine wave ?

Hi,

I have created a sine wave as follow:

Fs=2000;
t=0:1/Fs:1-1/Fs
f0=100;
y=sin(2*pi*f0*t)

Now, I would like to add 10 points with their value = 0 just before and after this sine wave. How could I do that ?

Thanks in advance!

[Adam Danz]

Does that mean there will be 10 inserted points prior to the first value, then 20 inserted points between each cycle, and then 10 inserted points at the end?

[Adam Danz]

Ok, but I have the same quesiton. If you add 10 points before AND after each cycle, then you're adding 20 points between each cycle. Is that what you want?

Answer 1

[Adam Danz]

It's not exactly clear what you're asking for but here are two solutions.

If you just want to add 10 points to the beginning and end of your entire signal

% number of elements to insert
nAdded = 10; 
% value to use as filler
filler = 0; 
% insert the values
fillVec = repmat(filler, 1, nAdded); 
expandedY = [fillVec, y, fillVec];     %Here's your new vector

If you want to add 10 points between each cycle of the sine curve including the beginning and end

% number of elements to insert
nAdded = 10; 
% value to use as filler
filler = 0; 

% lenght of 1 period (number of indices)
pdLength = length(y)/f0;

% insertion indices
origIdx = pdLength : pdLength : length(y);                         	%indices of y                         
expandedIdx = origIdx + cumsum(repmat(nAdded,1,length(origIdx)));   %indices of expanded y 
origIdx = [0, origIdx];                                                                         
expandedIdx = [0, expandedIdx]; 
% create new vector
expandedY = repmat(filler, 1, length(y) + f0*nAdded+nAdded);        %expanded y value
for i = 1 : length(expandedIdx)-1
    expandedY(expandedIdx(i)+nAdded+1 : expandedIdx(i+1)) = y(origIdx(i)+1 : origIdx(i+1)); 
end

[Adam Danz]

Which one? I'm still dying to know :D