I am using matlab to generate a set of gaussian distribution values, where mean is zero and variance is 1. If I want to change my varian to 0.5, what should I do? is it just multiply the output with o.5?
Here you'll find a good description of Gaussian or Normal distribution:
h**p://en.wikipedia.org/wiki/Normal_distribution
Other way of writing the formula:
According to that description your suggestion k=0.5*rand(1.5) is not right.
If you change the standard deviation (variance=standard_deviation^2) then
you must recalculate the formula again. By the way Excel has a function for
Gaussian or Normal distribution: NORMDIST. So you can also try it.
The relation between random variable X follows normal dist with any µ and σ and the random variable Z that follows normal dist with mean =0 and std dev = 1 is
Z= (X-µ)/σ
in other words X = σZ+ µ
Accordingly u have to multiply by the std dev (NOT variance)