modelDistributions

Demonstrates noise with different types of distributions

Extends from Modelica.Icons.Example (Icon for runnable examples).

Information

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

TypeNameDefaultDescription
SI.PeriodsamplePeriod0.02Sample period of all blocks
Realy_min-1Minimum value of band for random values
Realy_max3Maximum value of band for random values

Components

TypeNameDefaultDescription
Modelica.Blocks.Noise.GlobalSeedglobalSeed
RealuniformNoise_yuniformNoise.y
RealtruncatedNormalNoise_ytruncatedNormalNoise.y
Integernif time < 0.5 then 12 else 2
Modelica.Blocks.Noise.UniformNoiseuniformNoise
Modelica.Blocks.Noise.TruncatedNormalNoisetruncatedNormalNoise

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