Recurring Sequences of Numbers

Is there a way to declare v as a vector of numbers without a stopping point [0 -1 0 1 0 -1 0 1 ... n]? And from that I want to be able to use the number a to get all the entries of vector v. For example: a = 4 v = [0 -1 0 1]

Answer 1

[Stephen23]

>> fun = @(N)round(cos((1:N)*pi/2));
>> fun(10)
ans =
   0  -1   0   1   0  -1   0   1   0  -1
>> fun(4)
ans =
   0  -1   0   1

[C]

What would the function look like to do the same for [0 1 0 -1 ... n]? I've tried using the fun function with sin instead of cos, but the first value is 1 instead of 0.

[Stephen23]

You need to also offset the range of input values, e.g.:

(0:N-1)