Generate matrix of bits

Question

I would like to take an integer n defining the number of bits in my communication code and a vector defining the alphabet I am assigning to bits 0:n-1,

Answer 1

You can also do it like this:

M = 2 * (dec2bin(0:7, 3)=='1')-1;

That returns:

M =
    -1    -1    -1
    -1    -1     1
    -1     1    -1
    -1     1     1
     1    -1    -1
     1    -1     1
     1     1    -1
     1     1     1

However, it's slower. I get 0.0012s (dec2bin) against 0.0002s (meshgrid+bitget) for 1024 values and 10 bits.