how to randomly vary 2 numbers?

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Isabel
Isabel on 5 Jul 2012
Answered: Orazio Sorgonà on 2 Apr 2022
Hi! I want to generate a column of 30 randomly varying -1s and 1s. How can I do that? I was trying randi([-1:2:1],30,1) but that gives me zeros too and I don't want zeros, only -1 and 1. Thanks

Accepted Answer

John Petersen
John Petersen on 5 Jul 2012
x = 2*round(rand(30,1)) - 1;
  3 Comments
John Petersen
John Petersen on 5 Jul 2012
Edited: John Petersen on 5 Jul 2012
No it doesn't. Maybe you didn't grab the whole line?
Isabel
Isabel on 5 Jul 2012
Sorry, it does work, my bad. I think I din't copy the whole formula or something. Thank you very much for your answer!

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More Answers (2)

Andrei Bobrov
Andrei Bobrov on 5 Jul 2012
Edited: Andrei Bobrov on 5 Jul 2012
eg
A = (rand(5) > .5) + 0;
A(~A) = -1;
or
A = 2*randi([0 1],30,1) - 1;

Orazio Sorgonà
Orazio Sorgonà on 2 Apr 2022
I use
A = -1^(randi([1,2]));

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