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  • Totally OT: Colliding blocks that compute pi

    From Sylvia Else@21:1/5 to All on Tue Mar 18 16:05:33 2025
    XPost: sci.electronics.design

    https://www.youtube.com/watch?v=6dTyOl1fmDo

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  • From yeti@21:1/5 to Sylvia Else on Tue Mar 18 09:38:58 2025
    XPost: sci.electronics.design

    Sylvia Else <[email protected]d> wrote:

    https://www.youtube.com/watch?v=6dTyOl1fmDo

    The older videos about this way to get PI are among my favourite PI day
    videos. \o/

    I haven't seen this update yet. So far I only bookmarked it in my RSS
    feeds for somewhen later.

    --
    I do not bite, I just want to play.

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  • From yeti@21:1/5 to All on Tue Mar 18 10:06:58 2025
    XPost: sci.electronics.design

    Apropos PI day ... there is a PI related example in 9front's dc.1 man
    page ...

    <https://tio.run/##LU7BCoMwFLv3KwIeBhU36@bm/mL3sYNYN4TWqVWYX9/liRTS95KXENvEmGDo0P5qP7gW7@nrcSf28yHANkcDX/cY6k@rEmUQRpgqR5hwJc4oEDo8cYbroGGQwm6oSWmERfjiJlKBDG7kVCo38UvhZpQcTrRcKu4PhBUmlyu6LLMlMSPKE2HZNbExT2kwikGrZOn9lN3YUm6FY0capBKLOo8fXgh@m2L8Aw>

    ------------------------------------------------------------------------
    # pi example from 9front's dc.1 man page
    #
    1 sq 180 sr 60 st 2 si [ 3 li * 1 + d 1 + * 3 * su li 27 * 12 - lq * 5
    lr * + lt 5 * / d 48 + P sy 10 lq li d 2 * 1 - * * * 10 lu lq li 5 * 2 -
    * lr + ly lt * - * * sr sq lu lt * st li 1 + si lm x ] sm lm x ------------------------------------------------------------------------

    Do the used constants trigger someone's memory about which algorithm
    that may be?

    I do like playing with DC, but turning others' un-commented code back to readable maths so far was not among my just for fun DC puzzles.

    --
    1. Hitchhiker 25: (59) Scarcely pausing for breath, Vroomfondel shouted,
    "We don't demand solid facts! What we demand is a total absence of solid facts. I demand that I may or may not be Vroomfondel!"

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  • From yeti@21:1/5 to All on Tue Mar 18 22:23:46 2025
    XPost: sci.electronics.design

    ------------------------------------------------------------------------
    ~$ gdate -d@$(printf "%d" 0x7fffffff) +%H.%M
    03.14
    ------------------------------------------------------------------------

    Easy to remember, eh?

    But I still prefer 355/113.

    .-----+-----.
    .----+----. | The END |
    | Repent! | | is neigh! |
    ·----+----· ·-----+-----·
    | _ _ _ |
    |\°v° °v° ò.ó/|
    |_|\/|_|) /|_| ----------------------------^-^--^-^-----^-^----------------------------

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  • From john larkin@21:1/5 to All on Tue Mar 18 15:18:52 2025
    XPost: sci.electronics.design

    On Tue, 18 Mar 2025 15:02:29 -0700, john larkin <[email protected]>
    wrote:

    On Tue, 18 Mar 2025 16:05:33 +0800, Sylvia Else <[email protected]d>
    wrote:

    https://www.youtube.com/watch?v=6dTyOl1fmDo

    Pi keeps showing up uninvited.

    https://www.dropbox.com/scl/fi/evfwgzx10g1if5kvk2haj/SidewalkGraffiti.JPG?rlkey=p3r4dlvzqk5g45r7sy1ojtirw&raw=1

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  • From Lawrence D'Oliveiro@21:1/5 to All on Tue Mar 18 21:18:58 2025
    XPost: sci.electronics.design

    Did you know you can compute π just by dropping a needle?

    <https://en.wikipedia.org/wiki/Buffon%27s_needle_problem>

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  • From john larkin@21:1/5 to All on Tue Mar 18 15:02:29 2025
    XPost: sci.electronics.design

    On Tue, 18 Mar 2025 16:05:33 +0800, Sylvia Else <[email protected]d>
    wrote:

    https://www.youtube.com/watch?v=6dTyOl1fmDo

    Pi keeps showing up uninvited.

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  • From brian@21:1/5 to [email protected] on Thu Mar 20 11:34:20 2025
    XPost: sci.electronics.design

    In message <1r9ezj3.hf9oy51w6imhnN%[email protected]>, Sn!pe <[email protected]> writes
    john larkin <[email protected]> wrote:

    On Tue, 18 Mar 2025 15:02:29 -0700, john larkin <[email protected]>
    wrote:

    On Tue, 18 Mar 2025 16:05:33 +0800, Sylvia Else <[email protected]d>
    wrote:

    https://www.youtube.com/watch?v=6dTyOl1fmDo

    Pi keeps showing up uninvited.


    <https://www.dropbox.com/scl/fi/evfwgzx10g1if5kvk2haj/SidewalkGraffiti. >>JPG?rlkey=p3r4dlvzqk5g45r7sy1ojtirw&raw=1>

    An eul spill?


    Hamilton was guilty of a bit of graffiti in his day.

    <Https://www.irishtimes.com/news/royal-canal-bridge-stands-as-an-old-uniq ue-mathematical-shrine-1.318509>

    Brjan


    --
    Brian Howie

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  • From brian@21:1/5 to All on Thu Mar 20 11:29:43 2025
    XPost: sci.electronics.design

    In message <[email protected]ute>, yeti <[email protected]ute>
    writes >------------------------------------------------------------------------
    ~$ gdate -d@$(printf "%d" 0x7fffffff) +%H.%M
    03.14 >------------------------------------------------------------------------

    Easy to remember, eh?

    But I still prefer 355/113.

    .-----+-----.
    .----+----. | The END |
    | Repent! | | is neigh! |
    �----+----� �-----+-----�
    | _ _ _ |
    |\�v� �v� �.�/|
    |_|\/|_|) /|_|
    ----------------------------^-^--^-^-----^-^----------------------------


    I just remember 3.14159 - close enough for government work .

    Brian
    --
    Brian Howie

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  • From Stefan Ram@21:1/5 to yeti on Thu Mar 20 13:24:14 2025
    yeti <[email protected]ute> wrote or quoted:
    I haven't seen this update yet. So far I only bookmarked it in my RSS
    feeds for somewhen later.

    There was a time when mathematicians believed it was impossible
    to calculate a specific digit of pi without computing all
    preceding digits. This belief persisted until the discovery of
    the Bailey–Borwein–Plouffe (BBP) formula in 1995. The BBP formula
    allows for the extraction of any arbitrary digit of pi in its
    binary expansion (base 2) without calculating prior digits.
    This was groundbreaking and contrary to earlier assumptions.

    In 1996, Simon Plouffe extended this concept to base 10, enabling
    the calculation of specific decimal digits of pi without computing
    all preceding digits, though at a computational cost of O(n^3 (log
    n)^3), later improved to O(n^2) by Fabrice Bellard. Before these
    developments, no such efficient "digit extraction" algorithms were
    known, and it was widely assumed that such methods were not possible.

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  • From SH@21:1/5 to brian on Thu Mar 20 13:15:38 2025
    XPost: sci.electronics.design

    On 20/03/2025 11:29, brian wrote:
    In message <[email protected]ute>, yeti <[email protected]ute> writes
    ------------------------------------------------------------------------
    ~$ gdate -d@$(printf "%d" 0x7fffffff) +%H.%M
    03.14
    ------------------------------------------------------------------------

    Easy to remember, eh?

    But I still prefer 355/113.

                                          .-----+-----.
                        .----+----.       |  The END  |
                        | Repent! |       | is neigh! | >>                     ·----+----·       ·-----+-----·
                             |  _    _       _  |
                             |\°v°  °v°     ò.ó/|
                               |_|\/|_|)   /|_|
    ----------------------------^-^--^-^-----^-^----------------------------


    I just remember 3.14159 - close enough for government work .

    Brian

    How I wish I could calculate pi

    3.141592 - close enough for rocket science! :-)

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  • From Lawrence D'Oliveiro@21:1/5 to Stefan Ram on Fri Mar 21 06:05:14 2025
    On 20 Mar 2025 13:24:14 GMT, Stefan Ram wrote:

    later improved to O(n^2) by Fabrice Bellard.

    The same Fabrice Bellard who created FFmpeg and QEMU, among other things?

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  • From Lawrence D'Oliveiro@21:1/5 to All on Fri Mar 21 06:16:44 2025
    XPost: sci.electronics.design

    On Thu, 20 Mar 2025 13:15:38 +0000, SH wrote:

    How I wish I could calculate pi

    Your computer can do it!

    import decimal

    Dec = decimal.Decimal
    decctx = decimal.getcontext()
    decctx.prec = 64

    def decimal_pi():
    with decimal.localcontext() as decctx :
    decctx.prec += 2 # extra digits for intermediate steps
    t = Dec(3) # substitute 3.0 for regular floats
    lasts, s, n, na, d, da = 0, 3, 1, 0, 0, 24
    nr_steps = 0
    while s != lasts :
    nr_steps += 1
    lasts = s
    n, na = n + na, na + 8
    d, da = d + da, da + 32
    t = t * n / d
    s += t
    #end while
    #end with
    print("nr_steps = %d" % nr_steps)
    return +s # unary plus applies the new precision
    #end decimal_pi

    print(decimal_pi())

    output:

    nr_steps = 104
    3.141592653589793238462643383279502884197169399375105820974944592

    Taken from a presentation I did here <https://github.com/HamPUG/meetings/blob/master/2022/2022-11-14/ldo/Continued%20Fractions.ipynb>.

    I tried continued fractions, but found them a waste of time.

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  • From Lawrence D'Oliveiro@21:1/5 to brian on Fri Mar 21 06:18:31 2025
    XPost: sci.electronics.design

    On Thu, 20 Mar 2025 11:34:20 +0000, brian wrote:

    Hamilton was guilty of a bit of graffiti in his day.

    Aren't we glad that wasn’t the only place he wrote up his discovery ...

    “I have discovered a most marvellous proof, but this bridge is too small
    to contain it.”

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  • From Tom Del Rosso@21:1/5 to john larkin on Sun Mar 23 05:09:08 2025
    XPost: sci.electronics.design

    john larkin wrote:
    On Tue, 18 Mar 2025 15:02:29 -0700, john larkin <[email protected]>
    wrote:

    On Tue, 18 Mar 2025 16:05:33 +0800, Sylvia Else
    <[email protected]d> wrote:

    https://www.youtube.com/watch?v=6dTyOl1fmDo

    Pi keeps showing up uninvited.

    https://www.dropbox.com/scl/fi/evfwgzx10g1if5kvk2haj/SidewalkGraffiti.JPG?rlkey=p3r4dlvzqk5g45r7sy1ojtirw&raw=1

    e^(2pi)i = +1

    Shoulda been 6.28

    --
    Defund the Thought Police

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  • From candycanearter07@21:1/5 to john larkin on Sun Mar 23 14:30:03 2025
    XPost: sci.electronics.design

    john larkin <[email protected]> wrote at 22:02 this Tuesday (GMT):
    On Tue, 18 Mar 2025 16:05:33 +0800, Sylvia Else <[email protected]d>
    wrote:

    https://www.youtube.com/watch?v=6dTyOl1fmDo

    Pi keeps showing up uninvited.


    Pi is hidden in a lot of things.
    --
    user <candycane> is generated from /dev/urandom

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  • From piglet@21:1/5 to [email protected] on Sun Mar 23 15:39:11 2025
    XPost: sci.electronics.design

    candycanearter07 <[email protected]> wrote:
    john larkin <[email protected]> wrote at 22:02 this Tuesday (GMT):
    On Tue, 18 Mar 2025 16:05:33 +0800, Sylvia Else <[email protected]d>
    wrote:

    https://www.youtube.com/watch?v=6dTyOl1fmDo

    Pi keeps showing up uninvited.


    Pi is hidden in a lot of things.

    https://xkcd.com/687


    --
    piglet

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  • From john larkin @21:1/5 to fizzbintuesday@that-google-mail-dom on Sun Mar 23 10:09:26 2025
    XPost: sci.electronics.design

    On Sun, 23 Mar 2025 05:09:08 -0400, "Tom Del Rosso" <[email protected]> wrote:

    john larkin wrote:
    On Tue, 18 Mar 2025 15:02:29 -0700, john larkin <[email protected]>
    wrote:

    On Tue, 18 Mar 2025 16:05:33 +0800, Sylvia Else
    <[email protected]d> wrote:

    https://www.youtube.com/watch?v=6dTyOl1fmDo

    Pi keeps showing up uninvited.

    https://www.dropbox.com/scl/fi/evfwgzx10g1if5kvk2haj/SidewalkGraffiti.JPG?rlkey=p3r4dlvzqk5g45r7sy1ojtirw&raw=1

    e^(2pi)i = +1

    Shoulda been 6.28

    We have terrible graffiti thugs in San Francisco.

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  • From Lawrence D'Oliveiro@21:1/5 to Tom Del Rosso on Sun Mar 23 23:35:55 2025
    XPost: sci.electronics.design

    On Sun, 23 Mar 2025 05:09:08 -0400, Tom Del Rosso wrote:

    Shoulda been 6.28

    I tought I τ a puddy-tat ...

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  • From Scott Dorsey@21:1/5 to [email protected] on Sun Mar 23 20:24:46 2025
    XPost: sci.electronics.design

    candycanearter07 <[email protected]> wrote: >john larkin <[email protected]> wrote at 22:02 this Tuesday (GMT):
    On Tue, 18 Mar 2025 16:05:33 +0800, Sylvia Else <[email protected]d>
    wrote:

    https://www.youtube.com/watch?v=6dTyOl1fmDo

    Pi keeps showing up uninvited.

    Pi is hidden in a lot of things.

    So much of that is the fault of Euler's identity.
    --scott
    --
    "C'est un Nagra. C'est suisse, et tres, tres precis."

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  • From candycanearter07@21:1/5 to piglet on Mon Mar 24 17:00:04 2025
    XPost: sci.electronics.design

    piglet <[email protected]> wrote at 15:39 this Sunday (GMT):
    candycanearter07 <[email protected]> wrote:
    john larkin <[email protected]> wrote at 22:02 this Tuesday (GMT):
    On Tue, 18 Mar 2025 16:05:33 +0800, Sylvia Else <[email protected]d>
    wrote:

    https://www.youtube.com/watch?v=6dTyOl1fmDo

    Pi keeps showing up uninvited.


    Pi is hidden in a lot of things.

    https://xkcd.com/687


    There really is a XKCD for everything.
    --
    user <candycane> is generated from /dev/urandom

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  • From yeti@21:1/5 to [email protected] on Mon Mar 24 18:06:22 2025
    XPost: sci.electronics.design

    candycanearter07 <[email protected]> wrote:
    piglet <[email protected]> wrote at 15:39 this Sunday (GMT):
    candycanearter07 <[email protected]> wrote: >>>
    Pi is hidden in a lot of things.

    https://xkcd.com/687

    There really is a XKCD for everything.

    Indeed! \o/

    <https://xkcd-search.typesense.org/?xkcd%5Bquery%5D=everything>

    --
    xkcd - The blag of the webcomic - Randall 2019-08-26
    Chapter 19: How to Send a File <https://blog.xkcd.com/2019/08/26/how-to-send-a-file/>

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  • From candycanearter07@21:1/5 to yeti on Tue Mar 25 22:30:03 2025
    XPost: sci.electronics.design

    yeti <[email protected]ute> wrote at 17:24 this Monday (GMT):
    candycanearter07 <[email protected]> wrote:
    piglet <[email protected]> wrote at 15:39 this Sunday (GMT):
    candycanearter07 <[email protected]> wrote: >>>>
    Pi is hidden in a lot of things.

    https://xkcd.com/687

    There really is a XKCD for everything.

    Indeed! \o/

    <https://xkcd-search.typesense.org/?xkcd%5Bquery%5D=everything>


    Good to know theres a search if I ever need it ;)
    --
    user <candycane> is generated from /dev/urandom

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  • From Tom Del Rosso@21:1/5 to Sylvia Else on Sun May 4 12:12:04 2025
    XPost: sci.electronics.design

    Sylvia Else wrote:
    On 04-May-25 11:35 pm, Tom Del Rosso wrote:
    Sylvia Else wrote:
    https://www.youtube.com/watch?v=6dTyOl1fmDo

    But WHY does it compute pi in base ten?


    Because the right hand mass is increased by a factor of 10^2 each
    time. If it were increased, say, by a factor of 9^2, then the digits
    would be of Pi in base 9.

    Yeah, I hadn't watched it for a long time, but I just realized that as
    soon as I started to review it.


    --
    Defund the Thought Police

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  • From Tom Del Rosso@21:1/5 to Sylvia Else on Sun May 4 11:35:19 2025
    XPost: sci.electronics.design

    Sylvia Else wrote:
    https://www.youtube.com/watch?v=6dTyOl1fmDo

    But WHY does it compute pi in base ten?


    --
    Defund the Thought Police

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  • From Sylvia Else@21:1/5 to Tom Del Rosso on Sun May 4 23:41:01 2025
    XPost: sci.electronics.design

    On 04-May-25 11:35 pm, Tom Del Rosso wrote:
    Sylvia Else wrote:
    https://www.youtube.com/watch?v=6dTyOl1fmDo

    But WHY does it compute pi in base ten?


    Because the right hand mass is increased by a factor of 10^2 each time.
    If it were increased, say, by a factor of 9^2, then the digits would be
    of Pi in base 9.

    Sylvia.

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