• fyi, sympy integrator now default for sagemath?

    From Nasser M. Abbasi@21:1/5 to All on Fri Feb 4 02:42:46 2022
    Fyi;

    I just installed sagemath new release 9.5 on archlinux to get ready
    to run new build of CAS integration tests which will take long time.

    I noticed now sympy seems to be the default integrator:

    ==========================
    sage ┌────────────────────────────────────────────────────────────────────┐
    │ SageMath version 9.5, Release Date: 2022-01-30 │
    │ Using Python 3.10.2. Type "help()" for help. │ └────────────────────────────────────────────────────────────────────┘
    sage: x = var("x")

    sage: integrate(sqrt(1 + x ^ 3), x)
    1/3*x*gamma(1/3)*hypergeometric((-1/2, 1/3), (4/3,), -x^3)/gamma(4/3)

    But when I tried the 3 other CAS's I know about that can be used
    from sagemath integrate command, they all did not solve the above

    sage: integrate(sqrt(1 + x ^ 3), x, algorithm="fricas")
    integral(sqrt(x^3 + 1), x)

    sage: integrate(sqrt(1 + x ^ 3), x, algorithm="maxima")
    integrate(sqrt(x^3 + 1), x)

    sage: integrate(sqrt(1 + x ^ 3), x, algorithm="giac")
    integrate(sqrt(x^3 + 1), x)

    So I was wondering then how the first one obtained the answer.

    Then I tried sympy and that gave the above answer

    sage: integrate(sqrt(1 + x ^ 3), x, algorithm="sympy") 1/3*x*gamma(1/3)*hypergeometric((-1/2, 1/3), (4/3,), -x^3)/gamma(4/3)

    =======================

    Which tells me sympy is the default integrator. Unless sagemath 9.5
    is now smart enough to try different cas integrator one at a time
    behind the scene until it finds one which gives an answer?.

    I am not sure.

    In earlier versions of sagemath, maxima was the default integrator
    as far as I know. This looks like a new change.

    I am however still calling sympy 1.9 directly in Python
    and not via sagemath for making CAS integration test as it is
    more direct. This test has been completed. it took 5 weeks.
    Also Mathemtica 13 testing is completed.

    --Nasser

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