Ben Bacarisse wrote:
But that has to be about the process that gives rise to the data, not the data themselves.
If I say: "here is some random data..." you can't tell if it is or is not from a random source. I can, as a parlour trick, compress and recover this "random data" because I chose it.
Indeed. Another way to say it is that you can't conclude anything about the source from a sample size of one. If you have a large enough sample, then you can estimate a probability distribution, and calculate an entropy.
I think the argument that you can't compress arbitrary data is simpler ... it's obvious that it includes the results of previous compressions.
What? I don't see how "results of previous compressions" comes into it. The source has an entropy even if you're not doing compression at all. -- Greg -- https://mail.python.org/mailman/listinfo/python-list
