Uniform Random Number

Generate uniformly distributed random numbers for physical modeling


Physical Signals/Sources


The Uniform Random Number block generates uniformly distributed random numbers over the interval you specify. To generate normally (Gaussian) distributed random numbers, use the Random Number block.

The block behavior is the same as the Simulink® Uniform Random Number block (except that it generates a physical signal rather than a Simulink signal).

You have an option to specify an initial time offset as part of the Sample time parameter. In this case, the block outputs 0 until the simulation time reaches the offset value, at which point the random sequence starts.

Uniform Random Number blocks that use the same seed and parameters generate a repeatable sequence. The seed resets to the specified value each time a simulation starts.



Specify the minimum output value. The default is -1.


Specify the maximum output value. The default is 1.


Specify the starting seed for the random number generator. Output is repeatable for a given seed. The seed must be an integer in the range of 0 to (2^32 – 1). The default is 0.

Sample time

The value of the time step interval. The default step value is 1 s. To specify an initial time offset, enter the parameter value as [step, offset], otherwise the offset value is assumed to be 0. The offset must be less than the step size.


The block has one physical signal output port.

Introduced in R2013a

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