Random number in a specific range

Hello,,I wanna generate random numbers from range for example [-0.2,0.2] using matlab functions like randn or sth. thanks in advance.

Answer 1

[bym]

x = .4 * rand(100,1)-.2;

[Walter Roberson]

This answer is good if you want uniform distribution. If you want normal distribution then this answer will not work; see my Answer.

Answer 2

[Oleg Komarov]

You can scroll down the documentation of randn for an example.

EDIT You don't even need to scroll down.

[Walter Roberson]

The closest I see in the randn documentation is for a given mean and standard deviation. Nothing about a given range. Not for randn.

http://www.mathworks.com/help/techdoc/ref/randn.html

[Oleg Komarov]

Right, on the FEX there are contributions with random generators from truncated normal.

Answer 3

[Walter Roberson]

It is not possible to construct a normal distribution over a restricted range. By definition a normal distribution must have an infinite tail in both directions.

If you need something that is much like a normal distribution but is defined over a limited range, then consider using a beta distribution.