MATLAB Functions | Help Desk |
rand
Uniformly distributed random numbers and arrays
Y = rand(n) Y = rand(m,n) Y = rand([m n]) Y = rand(m,n,p,...) Y = rand([m n p...]) Y = rand(size(A)) rand s = rand('state')The
rand
function generates arrays of random numbers whose elements are uniformly distributed in the interval (0
,1
).
Y = rand(n)
returns an n
-by-n
matrix of random entries. An error message appears if n
is not a scalar.
Y = rand(m,n) or Y = rand([m n])
returns an m
-by-n
matrix of random entries.
Y = rand(m,n,p,...) or Y = rand([m n p...])
generates random arrays.
Y = rand(size(A))
returns an array of random entries that is the same size as A
.
rand
,
by itself, returns a scalar whose value changes each time it's referenced.
s = rand('state')
returns a 35-element vector containing the current state of the uniform generator. To change the state of the generator:rand('seed',0)
and rand('seed',j)
use the MATLAB 4 generator. rand('seed')
returns the current seed of the MATLAB 4 uniform generator. rand('state',j)
and rand('state',s)
use the MATLAB 5 generator.
R
=
rand(3,4)
may produce
R = 0.2190 0.6793 0.5194 0.0535 0.0470 0.9347 0.8310 0.5297 0.6789 0.3835 0.0346 0.6711This code makes a random choice between two equally probable alternatives.
if rand < .5 'heads' else 'tails' end
randn
Normally distributed random numbers and arrays
randperm
Random permutation
sprand
Sparse uniformly distributed random matrix
sprandn
Sparse normally distributed random matrix