Generate normally distributed random numbers
Sources
The Random Number block generates normally distributed random numbers. To generate uniformly distributed random numbers, use the Uniform Random Number block.
You can generate a repeatable sequence using any Random Number block with the same nonnegative seed and parameters. The seed resets to the specified value each time a simulation starts. By default, the block produces a sequence that has a mean of 0 and a variance of 1. To generate a vector of random numbers with the same mean and variance, specify the Seed parameter as a vector.
Avoid integrating a random signal, because solvers must integrate relatively smooth signals. Instead, use the BandLimited White Noise block.
The numeric parameters of this block must have the same dimensions after scalar expansion. If you select the Interpret vector parameters as 1D check box and the numeric parameters are row or column vectors after scalar expansion, the block outputs a 1D signal. If you clear the Interpret vector parameters as 1D check box, the block outputs a signal of the same dimensionality as the parameters.
The Random Number block outputs a real signal of type double
.
For more information, see
Data Types Supported by Simulink in
the Simulink^{®} documentation.
Specify the mean of the random numbers. The default is 0
.
Specify the variance of the random numbers. The default is 1
.
Specify the starting seed for the random number generator. The
default is 0
.
The seed must be 0 or a positive integer. Output is repeatable for a given seed.
Specify the time interval between samples. The default is 0.1
,
which matches the default sample time of the BandLimited
White Noise block. See
Specify Sample Time in the Simulink documentation
for more information.
If you select this check box and the other parameters are row or column vectors after scalar expansion, the block outputs a 1D signal. Otherwise, the block outputs a signal of the same dimensionality as the other parameters. For more information, see Determining the Output Dimensions of Source Blocks in the Simulink documentation.
Sample Time  Specified in the Sample time parameter 
Scalar Expansion  Yes, of parameters 
Dimensionalized  Yes 
Multidimensionalized  Yes 
ZeroCrossing Detection  No 
Algorithm 

The generator algorithm is identical to the one used in MATLAB
Version 4.0 by the rand
and randn
functions.
For details on the mcg16807
algorithm, see
Choosing
a Random Number Generator in the MATLAB^{®} documentation.
To use other algorithms supported by MATLAB in a Simulink model, generate a stream of random numbers in MATLAB, and store the output as a .mat file. Use this .mat file as the random number input for your simulation. For more information, see Creating and Controlling a Random Number Stream. To create multiple independent streams using MATLAB, see Multiple streams.
Note:
Using multiple seeds to generate multiple parallel independent
streams for a generator algorithm is not recommended for the 