How to fill a vector with just 2 elements -1 and 1, as a pseudorandom sequence?

I am currently experimenting with Matlab's features, and was looking to initialize a vector with just 2 numbers -1 and 1 like a pseudorandom sequence. Tried using the following:

X = randi([-1 1], 1, N);

But the vector contained 0 along with the 2 numbers, and realized the command actually fills up the vector with elements in a given interval [min, max].

Any suggestions on how to fill the vector with just the 2 numbers (only -1 and 1)?

Answer 1

[Star Strider]

Try this:

N = 10;
xpnt = randi(2, 1, N);
X = (-1).^xpnt;

producing (in this run):

X =
    -1     1     1     1    -1    -1    -1    -1     1     1

You can combine these into a single line of code if you wish. I kept them separate to demonstrate how it works.

[Karthik Ramesh Kamath]

Thank you, Star Strider. This was what I was looking for!

[Star Strider]

As always, my pleasure!