# Poisson Integer Generator

Generate Poisson-distributed random integers

## Library

Random Data Sources sublibrary of Comm Sources

## Description

The Poisson Integer Generator block generates random integers using a Poisson
distribution. The probability of generating a nonnegative integer
*k* is

$${\lambda}^{k}\mathrm{exp}(-\lambda )/(k!)$$

where λ is a positive number known as the Poisson parameter.

You can use the Poisson Integer Generator to generate noise in a binary
transmission channel. In this case, the Poisson parameter
**Lambda** should be less than 1, usually much
less.

### Attributes of Output Signal

The output signal can be a column or row vector, a two-dimensional
matrix, or a scalar. The number of rows in the output signal
corresponds to the number of samples in one frame and is determined
by the **Samples per frame** parameter. The number
of columns in the output signal corresponds to the number of
channels and is determined by the number of elements in the
**Lambda** parameter. See Sources and Sinks in
*Communications Toolbox™ User's Guide* for more
details.

## Parameters

**Lambda**The Poisson parameter λ. Specify λ as a scalar or row vector whose elements are real numbers. If

**Lambda**is a scalar, then every element in the output vector shares the same Poisson parameter. If**Lambda**is a row vector, then the number of elements correspond to the number of independent channels output from the block.**Source of initial seed**The source of the initial seed for the random number generator. Specify the source as either

`Auto`

or`Parameter`

. When set to`Auto`

, the block uses the global random number stream.**Note**When

**Source of initial seed**is`Auto`

in`Code generation`

mode, the random number generator uses an initial seed of zero. Therefore, the block generates the same random numbers each time it is started. Use`Interpreted execution`

to ensure that the model uses different initial seeds. If`Interpreted execution`

is run in`Rapid accelerator`

mode, then it behaves the same as`Code generation`

mode.**Initial seed**The initial seed value for the random number generator. Specify the seed as a nonnegative integer scalar.

**Initial seed**is available when the**Source of initial seed**parameter is set to`Parameter`

.**Sample time**Positive scalars specify the time in seconds between each sample of the output signal. If you set the sample time to

`-1`

, the output signal inherits the sample time from downstream. For information on the relationship between the**Sample time**and**Samples per frame**parameters, see Sample Timing.**Samples per frame**Samples per frame, specified as a positive integer indicating the number of samples per frame in one channel of the output data. For information on the relationship between

**Sample time**and**Samples per frame**, see Sample Timing.**Output data type**The output type of the block can be specified as a

`boolean`

,`uint8`

,`uint16`

,`uint32`

,`single`

, or`double`

. The default is`double`

.**Simulate using**Select the simulation mode.

`Code generation`

On the first model run, simulate and generate code. If the structure of the block does not change, subsequent model runs do not regenerate the code.

If the simulation mode is

`Code generation`

, System objects corresponding to the blocks accept a maximum of nine inputs.`Interpreted execution`

Simulate model without generating code. This option results in faster start times but can slow subsequent simulation performance.

## More About

## Extended Capabilities

## Version History

**Introduced before R2006a**