[PD] help_random/seed

[Lorenzo]

Maybe this may be of interest:

http://www.random.org/sounds/description/

Kind regards,
Loerenzo

IOhannes m zmoelnig wrote:
> Andrew Faraday wrote:
>> I'm fairly sure that [snapshot~] doesn't generate random numbers, but 
>> marks the current point of an audio signal. 
>
> indeed
>
>> Although this whole thing's got me thinking...
>> If you use [snapshot~], attached to a real world sound source [adc~] 
>> to generate random numbers, then increasing volume would increase the 
>> range of your random generation. For instance [adc~]|[snapshot~] 
>> (plus a bang)|[+ 1]|[* 10]|[int]
>
> first of all: [adc~] is _not_ a random number generator.
> it is an interface to the outside world. whatever is attached to your 
> soundcard (or whatever feeds [adc~] will determine what comes out of 
> [snapshot~].
>
> e.g. if i connect [adc~] to [dac~] then i might hear whatever is 
> recorded by my built-in microphone. i would not consider this "noise" 
> in the strict mathematical sense.
>
> if you connect an analog noise generator to your soundcard, then you 
> might get a nice (and truely random, though coloured) noise.
>
> now a real-world analog-digital converter always produces a (hopefully 
> small) bit of thermal nose, which can be used as either a noise-source 
> by itself (but take care, if you speak into the microphone...) or as a 
> truely-random seed generator for a pseudo-random number generator.
>
> the latter might give more what you would expect.
>
> the former has (apart from the "microphone" problem) the drawback, 
> that it will only generate a single "random" number per audio-block 
> (or to be precise: 64 for of them); which might be just too few for 
> your application...
>
>
>>
>> In this case a sound source at a solid 1 - -1 volume (such as [osc~]) 
>> would give you a number from 0 to 20, when the bang is sent.
>> but a quieter sound source e.g. 0.2 - -0.2 would provide a number 
>> from 0 - 4
>>
>> Anyone fault my logic?
>
> simple primary school mathematics?
> ([-1..1] + 1)*10 = [0..2]*10 = [0..20]
> ([-0.2..0.2] + 1)*10 = [0.8..1.2]*10 = [8..12]
>
> fmgasdr
> IOhannes
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>
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