MATLAB Function Reference    

Normally distributed random numbers and arrays



The randn function generates arrays of random numbers whose elements are normally distributed with mean 0, variance , and standard deviation .

Y = randn(n) returns an n-by-n matrix of random entries. An error message appears if n is not a scalar.

Y = randn(m,n) or Y = randn([m n]) returns an m-by-n matrix of random entries.

Y = randn(m,n,p,...) or Y = randn([m n p...]) generates random arrays.

Y = randn(size(A)) returns an array of random entries that is the same size as A.

randn, by itself, returns a scalar whose value changes each time it's referenced.

s = randn('state') returns a 2-element vector containing the current state of the normal generator. To change the state of the generator:

Resets the state to s.
Resets the generator to its initial state.
For integer j, resets the generator to its jth state.
Resets it to a different state each time.


Example 1. R = randn(3,4) may produce

For a histogram of the randn distribution, see hist.

Example 2. Generate a random distribution with a specific mean and variance . To do this, multiply the output of randn by the standard deviation , and then add the desired mean. For example, to generate a 5-by-5 array of random numbers with a mean of .6 that are distributed with a variance of 0.1

See Also

rand, randperm, sprand, sprandn

  rand randperm