||matlab 中 rand 函数是产生0到1的随机分布

1>、RAND:Uniformly distributed random numbers.

标准化分布的随机数

2>、RAND(N) is an N-by-N matrix with random entries, chosen from a uniform distribution on the interval (0.0,1.0).

rand(N)为随机生成一个在【0，1】之间的n维随机矩阵。

3>、RAND(M,N) and RAND([M,N]) are M-by-N matrices with random entries.

rand(M,N) and rand([M,N])随机生成一个在【0，1】之间的m，n维随机矩阵。

4>、RAND(M,N,P,...) or RAND([M,N,P,...]) generate random arrays.

rand(M,N,P) and rand([M,N])随机生成 P 个在【0，1】之间的m，n维随机矩阵。 5>、RAND with no arguments is a scalar whose value changes each time itis referenced. RAND(SIZE(A)) is the same size as A. 没有参数的rand是一个标量，它的值在每次被引用时都改变。rand( size(A) )是与 A 具有相同尺寸。6>、RAND produces pseudo-random numbers.The sequence of numbersgenerated is determined by the state of the                                        generator.Since MATLABresets the state at start-up, the sequence of numbers generated willbe the same unless the state                        is changed.

rand 产生伪随机数。生成的序列数由生成器的状态决定。由于 MATLAB 启动时重置状态，生成的序列数都是一样的除非状态改变。

7>、S = RAND('state') is a 35-element vector containing the current stateof the uniform generator.RAND('state',S) resets the                            state to S. 8>、RAND('state',0) resets the generator to its initial state.

重新恢复初始状态，刚运行matlab时候的状态

9>、RAND('state',J), for integer J, resets the generator to its J-th state.

安排种子产生第 j 个状态

10>、RAND('state',sum(100*clock)) resets it to a different state each time.

根据时间产生不同的随机数 ~~~~~~~~~~~~~~~~~~~~~~rand above~~~~~~~~~~~~~~~~~~~~~~~~~~

>> x = rand(1,10)

x =

Columns 1 through 6

0.3786 0.8116 0.5328 0.3507 0.9390 0.8759

Columns 7 through 10

0.5502 0.6225 0.5870 0.2077

(2)function2:randn

||matlab中 randn 函数是产生标准正态分布

1>、RANDN产生正态分布数的语法：

标准化分布的随机数 ;

RANDN(N) ：产生N× N的矩阵，其元素是按正态分布的数组；

RANDN(M,N) and RANDN([M,N])：产生M×N的矩阵；

RANDN(M,N,P,...) or RANDN([M,N,P...])产生随机序列；

2>、RANDN产生伪随机数的语法：

S = RANDN('state') 是一个二元向量，包括标准发生器的状态；

RANDN('state',S)：设置发生器的状态为S(即标准状态)；

RANDN('state',0)：设置发生器的初始状态；

RANDN('state',J)：J为整数，设置发生器到J阶状态；

3>、MATlAB 4.X应用一个单独的种子来产生随机数：

RANDN('seed',0) and RANDN('seed',J)作用与RANDN('state',0)和RANDN('state',J)一样，但使用Matlab 4.x随机数发生器。

RANDN('seed')：返回MATlAB 4.X发生器的当前种子。

>> x = randn(1,10)

x =

Columns 1 through 6

-0.1623 -0.1461 -0.5320 1.6821 -0.8757 -0.4838

Columns 7 through 10

-0.7120 -1.1742 -0.1922 -0.2741

(3)function3:randint

matlab 中 randint 是产生整数随机数，默认为 0 和 1

>> x = randi(1,10)

x =

1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

1 1 1 1 1 1 1 1 1 1

>> x = randint(1,10)

Warning: This is an obsolete function and may be removed in the

future.

Please use RANDI instead.

To disable this warning, type

warning('off','comm:obsolete:randint').

x =

1 1 1 0 1 0 1 1 0 0

>> x = RANDI(1,10)

Undefined function 'RANDI' for input arguments of type 'double'.