Generate random sequence of 1's and -1's in matlab

[Chinmaye]

How do i generate a random sequence of 1's and minus -1's in matlab with mean 0?

 

[pancho_hideboo]

x0 = 1:40;
y0 = 2*int32( randn( size(x0) ) >= 0.0 ) - 1;

Also see https://www.edaboard.com/showthread.php?373245#6

 

[Chinmaye]

This doesnt always give a mean of zero

 

[wwfeldman]

Re: generate random 1's and -1's in matlab

the rand function generates uniformly distributed random numbers

if you tell it to generate random numbers between 0 and 1,
you can convert those less than 0.5 to -1 and those greater than 0.5 to 1

 

[FvM]

This doesnt always give a mean of zero

By nature of random distribution, an arbitrary selected sample can't have exactly zero mean otherwise it's not random.

You may want to specify additional properties of the random distribution, e.g. maximal imbalance for a given sample length.

 

[pancho_hideboo]

This doesnt always give a mean of zero

If length of random sequence is enough large, average is zero.