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|    sci.math.symbolic    |    Symbolic algebra discussion    |    10,432 messages    |
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|    Message 9,556 of 10,432    |
|    bursejan@gmail.com to All    |
|    Re: Speeding up polynomial exponentiatio    |
|    11 Jul 17 04:27:05    |
      BTW, I expect there is a speed-up in all the       algorithm by using a method by Peter Henrici       originally deviced for rational numbers,              to keep the numbers small during basic       arithmetic. Possibly this can be also used       for multivariate polynomials here,              a cancellation of a fraction p/q would than       not anymore appear as a normalization operation       after the operation, but each operation would              proceed more cleverly. Anyway lets beat the       shit out of maxima in the future!              Am Dienstag, 11. Juli 2017 13:18:20 UTC+2 schrieb burs...@gmail.com:       > The small "bug" example pair I have is because       > the LCM gets too big, since I am not using the       > classical GB, a variant of it, which might still       >       > need some modding. But a bigger LCM, means also       > bigger p_new and q_new (look at the formulas), but       > we want the cancelled p,q as small as possible,       >       > so thats undesired.       >       > Am Dienstag, 11. Juli 2017 13:11:42 UTC+2 schrieb burs...@gmail.com:       > > The proof is very easy: Since p*q = GCD*LCM,       > > we have GCD = p*q/LCM, now check:       > >       > > p_new = p/(p*q/LCM) = LCM*p/(p*q) = LCM/q       > >       > > q_new = q/(p*q/LCM) = LCM*q/(p*q) = LCM/p       > >       > > See also here:       > > https://en.wikipedia.org/wiki/GCD_domain              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
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