WOLFRAM SYSTEM MODELER

Distributions

Demonstrates noise with different types of distributions

Diagram

Wolfram Language

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SystemModel["Modelica.Blocks.Examples.Noise.Distributions"]
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Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

This example demonstrates different noise distributions methods that can be selected for a Noise block. Both noise blocks use samplePeriod = 0.02 s, y_min=-1, y_max=3, and have identical fixedLocalSeed. This means that the same random numbers are drawn for the blocks. However, the random numbers are differently transformed according to the selected distributions (uniform and truncated normal distribution), and therefore the blocks have different output values. Simulation results are shown in the next diagram:

As can be seen, uniform noise is distributed evenly between -1 and 3, and truncated normal distribution has more values centered around the mean value 1.

Parameters (3)

samplePeriod

Value: 0.02

Type: Period (s)

Description: Sample period of all blocks

y_min

Value: -1

Type: Real

Description: Minimum value of band for random values

y_max

Value: 3

Type: Real

Description: Maximum value of band for random values

Outputs (2)

uniformNoise_y

Default Value: uniformNoise.y

Type: Real

truncatedNormalNoise_y

Default Value: truncatedNormalNoise.y

Type: Real

Components (3)

globalSeed

Type: GlobalSeed

Description: Defines global settings for the blocks of sublibrary Noise, especially a global seed value is defined

uniformNoise

Type: UniformNoise

Description: Noise generator with uniform distribution

truncatedNormalNoise

Type: TruncatedNormalNoise

Description: Noise generator with truncated normal distribution

Revisions

Date Description
June 22, 2015
DLR logo Initial version implemented by A. Klöckner, F. v.d. Linden, D. Zimmer, M. Otter.
DLR Institute of System Dynamics and Control