MATLAB Function Reference
  Go to function:
    Search    Help Desk 
rand    Examples   See Also

Uniformly distributed random numbers and arrays



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:

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


MATLAB 5 uses a new multiseed random number generator that can generate all the floating-point numbers in the closed interval Theoretically, it can generate over values before repeating itself. MATLAB 4 used random number generators with a single seed. 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

This code makes a random choice between two equally probable alternatives.

See Also

randn       Normally distributed random numbers and arrays

randperm    Random permutation

sprand      Sparse uniformly distributed random matrix

sprandn     Sparse normally distributed random matrix

[ Previous | Help Desk | Next ]