Random Number - Generate normally distributed random numbers

Library

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.

Data Type Support

The Random Number block outputs a real signal of type double. For more information, see Data Types Supported by Simulink in the Simulink documentation.

Parameters and Dialog Box

Mean

Specify the mean of the random numbers. The default is 0.

Variance

Specify the variance of the random numbers. The default is 1.

Seed

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.

Sample time

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 How to Specify the Sample Time in the Simulink documentation for more information.

Interpret vector parameters as 1-D

If you select this check box and the other parameters are row or column vectors after scalar expansion, the block outputs a 1-D 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.

Characteristics

Sample Time	Specified in the Sample time parameter
Scalar Expansion	Yes, of parameters
Dimensionalized	Yes
Multidimensionalized	Yes
Zero-Crossing Detection	No

See Also

Uniform Random Number

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