How to use randn function in matlab

Usage of randn function in matlab

randn function in MATLAB

matlab function

randn: A function that generates normally distributed random numbers or matrices

randn: Generates a positive mean with a mean of 0, a variance σ^2 = 1, and a standard deviation σ = 1 A function of a state distribution of random numbers or matrices.

Usage:

Y = randn(n)：返回一个n*n的随机项的矩阵。如果n不是个数量，将返回错误信息。
Y = randn(m,n) 或 Y = randn([m n])：返回一个m*n的随机项矩阵。
Y = randn(m,n,p,...) 或 Y = randn([m n p...])：产生随机数组。
Y = randn(size(A))：返回一个和A有同样维数大小的随机数组。

randn

Returns a quantity that changes every time.

s = randn('state')

Example

Example 1. R = randn(3,4) will generate a matrix

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.

Example 2. Generate a randomly distributed matrix with specified mean and variance: Just multiply the result produced by randn by the standard deviation and then add the expected mean. For example, the method to generate a 5*5 random number with a mean of 0.6 and a variance of 0.1 is as follows:

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

Other similar functions: rand, randperm, sprand, sprandn

Uniformly distributed random numbers or matrices

Syntax

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')

Description

rand function generates an array composed of random numbers uniformly distributed between (0, 1)

Y = rand(n) returns an n x n random matrix. If n is not a quantity, an error message is returned.

Y = rand(m,n) or Y = rand([m n]) Return A m x n random matrix

Y = rand(m,n,p,...) or Y = rand([m n p...]) generates a random array

Y = rand (size(A)) returns a random matrix

1 with the same size as A, rand(3)*-2 rand(3) is a 3*3 random matrix (the value range is 0~1 between) Then multiply each number by -2

2, and use matlab to randomly generate 60 positive numbers between 1 and 365 1 fix(365*rand(1,60));

3, use rand function to randomly pick 100 numbers x1, x2,..., x = rand(1,100) * 2 - 1

from -1 to 1

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