raylrnd

Rayleigh random numbers

Syntax

r = raylrnd(b)

r = raylrnd(b,sz1,...,szN)

r = raylrnd(b,sz)

Description

r = raylrnd(b) generates a random number from each Rayleigh distribution specified by the scale parameter b. You can specify b as a scalar, vector, matrix, or multidimensional array.

r = raylrnd(b,sz1,...,szN) generates an array of Rayleigh random numbers, where sz1,...,szN indicates the size of each dimension.

r = raylrnd(b,sz) generates an array of Rayleigh random numbers, where vector sz specifies size(r).

Examples

Generate Rayleigh Random Numbers

Generate random numbers from multiple Rayleigh distributions.

Generate a single random number from the Rayleigh distribution with scale parameter 6.

r = raylrnd(6)

r = 
11.4665

Generate a vector of random numbers from Rayleigh distributions with different scale parameters.

b = [6 4 1];
r = raylrnd(b)

r = 1×3

   15.6604    3.8602    0.4680

Generate Vector of Random Numbers from Same Rayleigh Distribution

Generate a vector of random numbers drawn from the Rayleigh distribution with scale parameter 2.

r = raylrnd(2,50,1)

r = 50×1

    2.0347
    3.6710
    5.1289
    2.8165
    0.6377
    4.0294
    1.7668
    1.0106
    7.1710
    5.9727
      ⋮

Plot a histogram of the result with a probability density function.

histfit(r,8,"rayleigh")

Generate Multidimensional Array of Rayleigh Random Numbers

Generate a 4-by-3-by-2 multidimensional array of random numbers from the Rayleigh distribution with scale parameter 0.5.

raylrnd(0.5,[4 3 2])

ans = 
ans(:,:,1) =

    0.3634    0.2168    1.8673
    1.0528    0.7632    1.4427
    1.1865    0.4943    1.6195
    0.4570    0.5986    1.6793


ans(:,:,2) =

    0.3975    0.0804    0.5475
    0.3788    0.7546    0.6039
    0.7728    0.7224    0.3680
    0.8619    0.7257    0.8735

Input Arguments

b — Scale parameter

positive scalar value | array of positive scalar values

Scale parameter of the Rayleigh distribution, specified as a positive scalar value or an array of positive scalar values.

To generate random numbers from multiple distributions, specify b using an array. If b is a scalar, then raylrnd expands the scalar argument into a constant array whose size matches the dimensions sz1,...,szN or sz. Each element in r is a random number generated from the distribution specified by the corresponding element in b.

Example: 2.5

Example: [3 4 5]

Data Types: single | double

sz1,...,szN — Size of each dimension (as separate arguments)

integers

Size of each dimension, specified as separate arguments of integers. If b is an array, then the specified dimensions sz1,...,szN must match the dimensions of b. The default values of sz1,...,szN are the dimensions of b.

• If you specify a single value sz1, then r is a square matrix of size sz1-by-sz1.

• If the size of any dimension is 0 or negative, then r is an empty array.

• Beyond the second dimension, raylrnd ignores trailing dimensions with a size of 1. For example, raylrnd(0.4,1,4,1,1,1,1) produces a 1-by-4 vector of random numbers from the Rayleigh distribution with scale 0.4.

Example: 7,6

Data Types: single | double

sz — Size of each dimension (as a row vector)

row vector of integers

Size of each dimension, specified as a row vector of integers. If b is an array, then the specified dimensions sz must match the dimensions of b. The default values of sz are the dimensions of b.

• If you specify a single value [sz1], then r is a square matrix of size sz1-by-sz1.

• If the size of any dimension is 0 or negative, then r is an empty array.

• Beyond the second dimension, raylrnd ignores any trailing dimensions with a size of 1. For example, raylrnd(0.4,[1 4 1 1 1 1]) produces a 1-by-4 vector of random numbers from the Rayleigh distribution with scale 0.4.

Example: [7 6]

Data Types: single | double

Output Arguments

r — Rayleigh random numbers

nonnegative scalar value | array of nonnegative scalar values

Rayleigh random numbers, returned as a nonnegative scalar value or an array of nonnegative scalar values with the dimensions determined by b, sz1,...,szN, or sz. Each element in r is a random number generated from the distribution specified by the corresponding scale parameter in b.

Alternative Functionality

• raylrnd is a function specific to the Rayleigh distribution. Statistics and Machine Learning Toolbox™ also offers the generic function random, which supports various probability distributions. To use random, create a RayleighDistribution probability distribution object and pass the object as an input argument or specify the probability distribution name and its parameter. Note that the distribution-specific function raylrnd is faster than the generic function random.

• To generate random numbers interactively, use randtool, a user interface for random number generation.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

The generated code can return a different sequence of numbers from the sequence returned by MATLAB^® if either of the following is true:

• The output is nonscalar.

• An input parameter is invalid for the distribution.

For more information on code generation, see Introduction to Code Generation and General Code Generation Workflow.

GPU Arrays

Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.

This function fully supports GPU arrays. For more information, see Run MATLAB Functions on a GPU (Parallel Computing Toolbox).

Version History

Introduced before R2006a