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Random Number

Generate normally distributed random numbers

  • Library:
  • Simulink / Sources

Description

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 Band-Limited 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 1-D check box, and the numeric parameters are row or column vectors after scalar expansion, the block outputs a 1-D signal. If you clear the Interpret vector parameters as 1-D check box, the block outputs a signal of the same dimensionality as the parameters.

Ports

Output

expand all

Output signal that is the generated random numbers falling within a normal Gaussian distribution. The output is repeatable for a given seed.

Data Types: double

Parameters

expand all

Specify the mean of the random numbers generated.

Programmatic Use

Block Parameter: Mean
Type: character vector
Values: scalar
Default: '0'

Specify the variance of the random numbers.

Programmatic Use

Block Parameter: Variance
Type: character vector
Values: scalar
Default: '1'

Specify the starting seed for the random number generator.

The output of number generated is repeatable for a given seed.

Programmatic Use

Block Parameter: Seed
Type: character vector
Values: scalar
Default: '0'

Specify the time interval between samples. The default is 0.1, which matches the default sample time of the Band-Limited White Noise block. See Specify Sample Time in the Simulink® documentation for more information.

Programmatic Use

Block Parameter: SampleTime
Type: character vector
Values: scalar
Default: '0.1'

Select this check box to output a vector of length N if the Constant value parameter evaluates to an N-element row or column vector.

  • When you select this check box, the block outputs a vector of length N if the Constant value parameter evaluates to an N-element row or column vector. For example, the block outputs a matrix of dimension 1-by-N or N-by-1.

  • When you clear this check box, the block does not output a vector of length N if the Constant value parameter evaluates to an N-element row or column vector.

Programmatic Use

Block Parameter: VectorParams1D
Type: character vector
Values: 'on' | 'off'
Default: 'on'

Block Characteristics

Data Types

double

Direct Feedthrough

No

Multidimensional Signals

Yes

Variable-Size Signals

No

Zero-Crossing Detection

No

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Introduced before R2006a