MATLAB: How to add on to y in a for loop? Insert zeros into vector. cody question

basicfor statement

The code returns 5 0 0.
I used the debugger. The for loop made 1 0 0; 2 0 0;….; 5 0 0
The goal is to return y = [1 0 0 2 0 0 3 0 0 4 0 0 5 0 0]
x = [1 2 3 4 5];
n = 2;
% zero = zeros(1,n)
% [x(1) 0 0 x(2) 0 0]
y = [];
zero=zeros(1,n);
% How can I combine y?
for i = 1:1:length(x)
    y = [x(i),zero]
end

Best Answer

A hint:
y = [1,2,3]
Then how do you create this output:
[1,2,3,6,7,8]
? Do you see it? You need to include the former value of y.
Another idea:
Create the vector of zeros at first, which has (n+1)*length(x) elements. Then use this as index:
1 + (0:length(x)-1)) * (n + 1)
or equivalently (find out, why this creates the same result!)
1:(n+1):length(y)
when y is the created vector of zeros.
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