MATLAB Function Reference |
Normally distributed random numbers and arrays
Syntax
Y = randn(n) Y = randn(m,n) Y = randn([m n]) Y = randn(m,n,p,...) Y = randn([m n p...]) Y = randn(size(A)) randn s = randn('state')
Description
The randn
function generates arrays of random numbers whose elements are normally distributed with mean 0, variance , and standard deviation .
returns an Y = randn(n)
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.
returns an array of random entries that is the same size as Y = randn(size(A))
A
.
by itself, returns a scalar whose value changes each time it's referenced. randn
,
s = randn('state')
returns a 2-element vector containing the current state of the normal generator. To change the state of the generator:
Examples
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
x = .6 + sqrt(0.1) * randn(5) x = 0.8713 0.4735 0.8114 0.0927 0.7672 0.9966 0.8182 0.9766 0.6814 0.6694 0.0960 0.8579 0.2197 0.2659 0.3085 0.1443 0.8251 0.5937 1.0475 -0.0864 0.7806 1.0080 0.5504 0.3454 0.5813
See Also
rand
, randperm
, sprand
, sprandn
rand | randperm |
© 1994-2005 The MathWorks, Inc.