MATLAB: How to generate a random decimal number between -1 and 1

Question

I'm trying to use rand below but it is giving me [ ].

rand([-1 1]);

Answer 1

The inputs to rand define its output size, not the output value range. Its range is fixed to 0..1, but you can adjust generate other values using some simple operations:

2*rand()-1
ans = -0.7192