So, since Theo Verelst still doesn't understand, let's discuss it again the Nth time:
Shannon defines entropy as the minimum average length of a message in bits when you want to transmit messages of a probabilistic ensemble. He dismisses the codebook size and the size of the decoder/receiver program, assuming them to be zero. Since without the codebook (either transmitted or pre-agreed), the messages cannot be decoded, and your transmission is entirely useless. Therefore, I consider the codebook the integral part of the transmission, hence its size is always nonzero (either transmitted or pre-agreed), therefore the actual entropy is always nonzero, even in the case of a single message with 100% probability. (I gave some formulas earlier about this.) The algorithmic information theory folks (Kolmogorov, Solomonoff, Chaitin, etc.) define entropy in relation to some sort of machine, typically an abstract Turing machine. Once an eval function is defined for that machine, the precise algorithmic entropy can be defined as the minimum length binary program that outputs that string of bits. This is also always nonzero, and is not a function of probability. (See Kolmogorov complexity / algorithmic information theory.) Entropy _rate_ is the measure of average information per symbol as the number of symbols asymptotically reaches infinity. There's a problem with this - when was the last time you made an infinite amount of observations? Since your lifetime is finite, you can never process an infinite amount of data, so in practice, dividing the total entropy by the number of symbols will never actually reach zero. Since the actual entropy of a signal is always nonzero, the only way the measured entropy _rate_ of a signal can be zero is by making an infinite amount of observations, since finite/infinite = zero. So that can happen only in theory, but never in practice. And since all this was already discussed, what I still don't understand: Why didn't you guys paid attention the first time? Why do I need to repeat everything 3-4-5 times? -P _______________________________________________ music-dsp mailing list music-dsp@music.columbia.edu https://lists.columbia.edu/mailman/listinfo/music-dsp