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| Synthesizer.SampleRateContext.Noise | | Portability | requires multi-parameter type classes | | Stability | provisional | | Maintainer | synthesizer@henning-thielemann.de |
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| Description |
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| Synopsis |
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| white :: (C yv, Random yv, C q') => q' -> q' -> T t q' -> T y q' yv | | | whiteBandEnergy :: (C yv, Random yv, C q') => q' -> T t q' -> T y q' yv | | | randomPeeks :: (C q, Random q, Ord q, C q', C q q') => T q q' -> T q q' q -> [Bool] | | | whiteGen :: (C yv, Random yv, RandomGen g, C q') => g -> q' -> q' -> T t q' -> T y q' yv | | | whiteBandEnergyGen :: (C yv, Random yv, RandomGen g, C q') => g -> q' -> T t q' -> T y q' yv | | | randomPeeksGen :: (C q, Random q, Ord q, C q', C q q', RandomGen g) => g -> T q q' -> T q q' q -> [Bool] |
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| Documentation |
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| :: (C yv, Random yv, C q') | | | => q' | width of the frequency band
| | -> q' | volume caused by the given frequency band
| | -> T t q' | | | -> T y q' yv | noise
| Uniformly distributed white noise.
The volume is given by two values:
The width of a frequency band and the volume caused by it.
The width of a frequency band must be given
in order to achieve independence from sample rate.
See whiteBandEnergy.
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| :: (C yv, Random yv, C q') | | | => q' | energy per frequency band
| | -> T t q' | | | -> T y q' yv | noise
| Uniformly distributed white noise.
Instead of an amplitude you must specify a value
that is like an energy per frequency band.
It makes no sense to specify an amplitude
because if you keep the same signal amplitude
while increasing the sample rate by a factor of four
the amplitude of the frequency spectrum halves.
Thus deep frequencies would be damped
when higher frequencies enter.
Example:
If your signal is a function from time to voltage,
the amplitude must have the unit volt^2*second,
which can be also viewed as volt^2/hertz.
Note that the energy is proportional to the square of the signal amplitude.
In order to double the noise amplitude,
you must increase the energy by a factor of four.
Using this notion of amplitude
the behaviour amongst several frequency filters
is quite consistent but a problem remains:
When the noise is quantised
then noise at low sample rates and noise at high sample rates
behave considerably different.
This indicates that quantisation should not just pick values,
but it should average over the hold periods.
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| :: (C q, Random q, Ord q, C q', C q q') | | | => T q q' | | | -> T q q' q | momentary densities (frequency),
p means that there is about one peak
in the time range of 1/p.
| | -> [Bool] | Every occurence of True represents a peak.
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| :: (C yv, Random yv, RandomGen g, C q') | | | => g | random generator, can be used to choose a seed
| | -> q' | width of the frequency band
| | -> q' | volume caused by the given frequency band
| | -> T t q' | | | -> T y q' yv | noise
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| :: (C yv, Random yv, RandomGen g, C q') | | | => g | random generator, can be used to choose a seed
| | -> q' | energy per frequency band
| | -> T t q' | | | -> T y q' yv | noise
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| :: (C q, Random q, Ord q, C q', C q q', RandomGen g) | | | => g | random generator, can be used to choose a seed
| | -> T q q' | | | -> T q q' q | momentary densities (frequency),
p means that there is about one peak
in the time range of 1/p.
| | -> [Bool] | Every occurence of True represents a peak.
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| Produced by Haddock version 2.4.2 |
