# randn

## Purpose

Normally distributed random numbers and matrices.

## Synopsis

    Y = randn(n)
    Y = randn(m,n)
    Y = randn(size(A))
    randn('seed')
    randn('seed',n)
    randn

## Description

`randn` generates random numbers and matrices whose elements are normally distributed with mean 0 and variance 1.

`randn(n)` is an `n`-by-`n` matrix with random entries.

`randn(m,n)` is an `m`-by-`n` matrix with random entries.

`randn(size(A))` is the same size as `A` and has random entries.

`randn('seed')` returns the current value of the seed used by the generator.

`randn('seed',n)` sets the seed to `n`. `randn('seed',0)` sets the seed to its startup value.

`randn` with no arguments is a scalar whose value changes each time it is referenced.

The functions `rand` and `randn` maintain separate generators with separate seeds.

## Examples

If `randn` has not yet been used during a particular MATLAB session, then `R = randn(3,4)` produces

     R =
        1.1650    0.3516    0.0591    0.8717
        0.6268   -0.6965    1.7971   -1.4462
        0.0751    1.6961    0.2641   -0.7012

For a histogram of the `randn` distribution, see `hist`.

## Algorithm

`randn` uses a second copy of the uniform generator used by `rand` and transforms the resulting values according to the algorithm in [1].

## See Also

    rand, randperm

## References

[1] G.E. Forsythe, M.A. Malcolm and C.B. Moler, Computer Methods for Mathematical Computations, Prentice-Hall, 1977.

(c) Copyright 1994 by The MathWorks, Inc.