modelAutomaticSeed

Demonstrates noise with startTime and automatic local seed for UniformNoise

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

Information

This example demonstrates manual and automatic seed selection of UniformNoise blocks, as well as starting the noise at startTime = 0.5 s with an output value of y = -1 before this time. All noise blocks in this example generate uniform noise in the band y_min=-1 .. y_max=3 with samplePeriod = 0.01 s.

The blocks automaticSeed1, automaticSeed2, automaticSeed3 use the default option to automatically initialize the pseudo random number generators of the respective block. As a result, different noise is generated, see next diagram:

The blocks manualSeed1, manualSeed2, manualSeed3 use manual selection of the local seed (useAutomaticLocalSeed = false). They use a fixedLocalSeed of 1, 2, and 3 respectively. Again, different noise is generated, see next diagram:

Try to set fixedLocalSeed = 1 in block manualSeed2. As a result, the blocks manualSeed1 and manualSeed2 will produce exactly the same noise.

Parameters

TypeNameDefaultDescription
SI.TimestartTime0.5Start time of noise
Realy_off-1.0Output of block before startTime

Components

TypeNameDefaultDescription
RealmanualSeed1_ymanualSeed1.y
RealmanualSeed2_ymanualSeed2.y
RealmanualSeed3_ymanualSeed3.y
Modelica.Blocks.Noise.GlobalSeedglobalSeed
Modelica.Blocks.Noise.UniformNoiseautomaticSeed1
Modelica.Blocks.Noise.UniformNoiseautomaticSeed2
Modelica.Blocks.Noise.UniformNoiseautomaticSeed3
Modelica.Blocks.Noise.UniformNoisemanualSeed1
Modelica.Blocks.Noise.UniformNoisemanualSeed2
Modelica.Blocks.Noise.UniformNoisemanualSeed3

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