random
Random numbers
Syntax
Description
R = random(___,sz1,...,szN)sz1,...,szN indicates the size of each
dimension.
Examples
Generate one random number from the normal distribution with the mean equal to 1 and the standard deviation equal to 5. Specify the distribution name 'Normal' and the distribution parameters.
rng('default') % For reproducibility mu = 1; sigma = 5; r = random('Normal',mu,sigma)
r = 3.6883
Create a normal distribution object and generate one random number using the object.
Create a normal distribution object with the mean equal to 1 and the standard deviation equal to 5.
mu = 1; sigma = 5; pd = makedist('Normal','mu',mu,'sigma',sigma);
Generate one random number from the distribution.
rng('default') % For reproducibility r = random(pd)
r = 3.6883
Save the current state of the random number generator. Then generate a random number from the Poisson distribution with rate parameter 5.
s = rng;
r = random('Poisson',5)r = 5
Restore the state of the random number generator to s, and then create a new random number. The value is the same as before.
rng(s);
r1 = random('Poisson',5)r1 = 5
Create a matrix of random numbers with the same size as an existing array. Use the stable distribution with shape parameters 2 and 0, scale parameter 1, and location parameter 0.
A = [3 2; -2 1];
sz = size(A);
R = random('Stable',2,0,1,0,sz)R = 2×2
0.7604 -3.1945
2.5935 1.2193
You can combine the previous two lines of code into a single line.
R = random('Stable',2,0,1,0,size(A))R = 2×2
0.4508 -0.6132
-1.8494 0.4845
Create a Weibull probability distribution object using the default parameter values.
pd = makedist('Weibull')pd =
WeibullDistribution
Weibull distribution
A = 1
B = 1
Generate random numbers from the distribution.
rng('default') % For reproducibility r = random(pd,10000,1);
Construct a histogram using 100 bins with a Weibull distribution fit.
histfit(r,100,'weibull')
Create a standard normal probability distribution object.
pd = makedist('Normal')pd =
NormalDistribution
Normal distribution
mu = 0
sigma = 1
Generate a 2-by-3-by-2 array of random numbers from the distribution.
r = random(pd,[2,3,2])
r =
r(:,:,1) =
0.5377 -2.2588 0.3188
1.8339 0.8622 -1.3077
r(:,:,2) =
-0.4336 3.5784 -1.3499
0.3426 2.7694 3.0349
Input Arguments
Output Arguments
Alternative Functionality
randomis a generic function that accepts either a distribution by its namenameor a probability distribution objectpd. It is faster to use a distribution-specific function, such asrandnandnormrndfor the normal distribution andbinorndfor the binomial distribution. For a list of distribution-specific functions, see Supported Distributions.To generate random numbers interactively, use
randtool, a user interface for random number generation.
