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Thread: Why SSE in PAQ8 works on un-stretched probabilities?

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    Why SSE in PAQ8 works on un-stretched probabilities?

    I've looked at PAQ8L source code here https://github.com/JohannesBuchner/p...aq8l/paq8l.cpp and saw that SSE/ APM (I guess APM is PAQ8's name for SSE) works on linear probabilities. That will (I think) give big rounding error when dealing with skewed probabilities (like 0.01 or 0.99). Shouldn't SSE work better on stretched probabilities?

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    Doesn't the line 1259 pr=stretch(pr); stretch the probability?

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    Piotr Tarsa (21st April 2018)

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    Yes Somehow I missed that. Perhaps the repeating stretching and squashing misled me.

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