Re: [music-dsp] Some DSP with a dsPIC33F

2014-10-14 Thread Eric Brombaugh
I've used the dsPIC33FJ64GP802 with on-chip stereo audio DAC in a couple of well-recieved mass-produced products (Euro-rack synth modules) and the on-chip DAC is decent enough. It does suffer from some limit cycling at 1/2 the sample rate if you try to drive constant data, but I always ran it

Re: [music-dsp] entropy

2014-10-14 Thread Peter S
On 14/10/2014, ro...@khitchdee.com ro...@khitchdee.com wrote: Peter, How would you characterize the impact of your posts on the entropy of this mailing list, starting with the symbol space that get's defined by the different perspectives on entropy :-) I merely showed that: 1) 'entropy'

Re: [music-dsp] entropy

2014-10-14 Thread Peter S
Again, the minimal number of 'yes/no' questions needed to guess your message with 100% probability is _precisely_ the Shannon entropy of the message: For the case of equal probabilities (i.e. each message is equally probable), the Shannon entropy (in bits) is just the number of yes/no questions

Re: [music-dsp] entropy

2014-10-14 Thread Peter S
Another way of expressing what my algorithm does: it estimates 'decorrelation' in the message by doing a simple first-order approximation of decorrelation between bits. The more random a message is, the more decorrelated their bits are. Otherwise, if the bits are correlated, that is not random and

Re: [music-dsp] entropy

2014-10-14 Thread Max Little
Longest discussion thread so far I think! The discussion reminded me of more general measures of entropy than Shannon's, examples are the Renyi entropies: http://en.wikipedia.org/wiki/R%C3%A9nyi_entropy Some might find it amusing and relevant to this discussion that the 'Hartley entropy' H_0 is

Re: [music-dsp] entropy

2014-10-14 Thread Peter S
So, instead of academic hocus-pocus and arguing about formalisms, what I'm rather concerned about is: - What are the real-world implications of the Shannon entropy problem? - How could we possibly use this to categorize arbitrary data? -- dupswapdrop -- the music-dsp mailing list and website:

Re: [music-dsp] entropy

2014-10-14 Thread Peter S
On 14/10/2014, Max Little max.a.lit...@gmail.com wrote: P.S. Any chance people could go offline for this thread now please? It's really jamming up my inbox and I don't want to unsubscribe ... Any chance your mailbox has the possibility of setting up a filter that moves messages with the

Re: [music-dsp] entropy

2014-10-14 Thread Peter S
On 14/10/2014, Max Little max.a.lit...@gmail.com wrote: Some might find it amusing and relevant to this discussion that the 'Hartley entropy' H_0 is defined as the base 2 log of the cardinality of the sample space of the random variable ... Which implies, that if the symbol space is binary (0

Re: [music-dsp] Some DSP with a dsPIC33F

2014-10-14 Thread STEFFAN DIEDRICHSEN
Eric, Are you using the MPLab IDE? I saw that it runs on Mac OS X as well, which makes it a bit more attractive. Best, Steffan On 14 Oct 2014, at 08:09, Eric Brombaugh ebrombau...@cox.net wrote: I've used the dsPIC33FJ64GP802 with on-chip stereo audio DAC in a couple of well-recieved

Re: [music-dsp] entropy

2014-10-14 Thread Peter S
Which is another way of saying: a fully decorrelated sequence of bits has the maximum amount of entropy. So if we try to estimate the 'decorrelation' (randomness) in the signal, then we can estimate 'entropy'. -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ,

Re: [music-dsp] entropy

2014-10-14 Thread Max Little
Well, it just says that there is a measure of information for which the actual distribution of symbols is (effectively) irrelevant. Which is interesting in it's own right ... Max On 14 October 2014 11:59, Peter S peter.schoffhau...@gmail.com wrote: On 14/10/2014, Max Little

Re: [music-dsp] entropy

2014-10-14 Thread Peter S
On 14/10/2014, Max Little max.a.lit...@gmail.com wrote: Well, it just says that there is a measure of information for which the actual distribution of symbols is (effectively) irrelevant. Which is interesting in it's own right ... Feel free to think outside the box. Welcome to the real world,

Re: [music-dsp] entropy

2014-10-14 Thread Max Little
Prescient. Apparently, Kolmogorov sort of, perhaps, agreed: Discussions of information theory do not usually go into this combinatorial approach [that is, the Hartley function] at any length, but I consider it important to emphasize its logical independence of probabilistic assumptions, from Three

Re: [music-dsp] Some DSP with a dsPIC33F

2014-10-14 Thread Eric Brombaugh
Yes, I use MPLAB X on Mac, Linux and Windows for developing on Microchip MCUs. It's... quirky... but it does work. Eric On 10/14/2014 04:08 AM, STEFFAN DIEDRICHSEN wrote: Eric, Are you using the MPLab IDE? I saw that it runs on Mac OS X as well, which makes it a bit more attractive. --

Re: [music-dsp] entropy

2014-10-14 Thread Peter S
On 14/10/2014, Sampo Syreeni de...@iki.fi wrote: We do know this stuff. We already took the red pill, *ages* ago. Peter's problem appears to be that he's hesitant to take the plunge into the math, proper. Starting with the basics Didn't you recently tell us that you have no clue of 'entropy

Re: [music-dsp] entropy

2014-10-14 Thread Ethan Duni
Although, it's interesting to me that you might be able to get some surprising value out of information theory while avoiding any use of probability ... Hartley entropy doesn't avoid any use of probability, it simply introduces the assumption that all probabilities are uniform which greatly

Re: [music-dsp] entropy

2014-10-14 Thread Max Little
Hartley entropy doesn't avoid any use of probability, it simply introduces the assumption that all probabilities are uniform which greatly simplifies all of the calculations. How so? It's defined as the log cardinality of the sample space. It is independent of the actual distribution of the

Re: [music-dsp] entropy

2014-10-14 Thread Sampo Syreeni
On 2014-10-14, Max Little wrote: Hartley entropy doesn't avoid any use of probability, it simply introduces the assumption that all probabilities are uniform which greatly simplifies all of the calculations. How so? It's defined as the log cardinality of the sample space. It is independent

Re: [music-dsp] entropy

2014-10-14 Thread Max Little
Right, and that is exactly equivalent to using Shannon entropy under the assumption that the distribution is uniform. Well, we'd probably have to be clearer about that. The Hartley entropy is invariant to the actual distribution (provided all the probabilities are non-zero, and the sample space

Re: [music-dsp] entropy

2014-10-14 Thread Max Little
Hartley entropy doesn't avoid any use of probability, it simply introduces the assumption that all probabilities are uniform which greatly simplifies all of the calculations. How so? It's defined as the log cardinality of the sample space. It is independent of the actual distribution of the

Re: [music-dsp] entropy

2014-10-14 Thread Sampo Syreeni
On 2014-10-14, Max Little wrote: Hmm .. don't shoot the messenger! I merely said, it's interesting that you don't actually have to specify the distribution of a random variable to compute the Hartley entropy. No idea if that's useful. Math always has this precise tradeoff: more general but

Re: [music-dsp] entropy

2014-10-14 Thread Theo Verelst
Max Little wrote: ... Well, we'd probably have to be clearer about that. The Hartley entropy is invariant to the actual distribution Without going into the comparison of wanting to be able to influence the lottery to achieve a higher winning chance, I looked up the Shannon/Hartley theorem,

Re: [music-dsp] entropy

2014-10-14 Thread Ethan Duni
The Hartley entropy is invariant to the actual distribution (provided all the probabilities are non-zero, and the sample space remains unchanged). No, the sample space does not require that any probabilities are nonzero. It's defined up-front, independently of any probability distribution.

Re: [music-dsp] entropy

2014-10-14 Thread Max Little
OK yes, 0^0 = 1. Delete the bit about probabilities needing to be non-zero I guess! Think you're taking what I said too seriously, I just said it's an interesting formula! Kolmogorov seemed to think so too. M. On 14 October 2014 18:37, Ethan Duni ethan.d...@gmail.com wrote: The Hartley entropy

Re: [music-dsp] entropy

2014-10-14 Thread Max Little
Yes, don't have time for a long answer, but all elegantly put. I'm just reiterating the formula. And saying it's interesting. Maths is really just patterns, lots of them are interesting to me, regardless of whether there is any other extrinsic 'meaning' to those patterns. M. On 14 October 2014

Re: [music-dsp] entropy

2014-10-14 Thread Sampo Syreeni
On 2014-10-14, Max Little wrote: Maths is really just patterns, lots of them are interesting to me, regardless of whether there is any other extrinsic 'meaning' to those patterns. In that vein, it might even be the most humanistic of sciences. Moreso even than poetry:

Re: [music-dsp] entropy

2014-10-14 Thread Max Little
If you look at the real audio signals out there, which statistic would you expect them to follow under the Shannonian framework? A flat one? Or alternatively, what precise good would it do to your analysis, or your code, if you went with the equidistributed, earlier, Hartley framework? Would

Re: [music-dsp] entropy

2014-10-14 Thread Ethan Duni
The relevant limit here is: lim x*log(x) = 0 x-0 It's pretty standard to introduce a convention of 0*log(0) = 0 early on in information theory texts, since it avoids a lot of messy delta/epsilon stuff in the later exposition (and since the results cease to make sense without it, with empty