Uniform White Noise VI
Owning Palette: Signal Generation VIs
Installed With: Full Development System
Generates a uniformly distributed, pseudorandom pattern whose values are in the range [-a:a], where a is the absolute value of amplitude.
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samples is the number of the samples of the uniform white noise. samples must be greater than 0. The default is 128. |
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amplitude is the amplitude of uniform white noise. The default is 1.0. |
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seed, when greater than 0, causes reseeding of the noise sample generator. The default is –1. LabVIEW maintains the internal seed state independently for each instance of this reentrant VI. For a specific instance of this VI, if seed is less than or equal to 0, LabVIEW does not reseed the noise generator, and the noise generator resumes producing noise samples as a continuation of the previous noise sequence. |
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uniform white noise contains the uniformly distributed, pseudorandom pattern. |
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error returns any error or warning from the VI. You can wire error to the Error Cluster From Error Code VI to convert the error code or warning into an error cluster. |
Uniform White Noise Details
The Uniform White Noise VI generates the pseudorandom sequence using a modified version of the Very-Long-Cycle random number generator algorithm. The pseudorandom number generator implements a triple-seeded linear congruential algorithm. Given that the probability density function, f(x), of the uniformly distributed uniform white noise is
,
where a is the absolute value of the specified amplitude.
The following equations define the expected mean value, µ, and the expected standard deviation value, 
, of the pseudorandom sequence:
µ = E{x} = 0
The pseudorandom sequence produces approximately 290 samples before the pattern repeats itself.
You can use uniform white noise as a stimulus to measure the frequency response of amplifiers and electronic filters.
You also can use the Uniform White Noise Waveform VI to generate a uniform white noise signal or the Continuous Random VI to generate random values from a continuous uniform-distributed variate.