• Re: More complex numbers than reals?

    From Ben Bacarisse@21:1/5 to Chris M. Thomasson on Mon Jul 8 23:59:20 2024
    "Chris M. Thomasson" <[email protected]> writes:

    Are there "more" complex numbers than reals?

    If you ask this in an appropriate group (sci.math?) I'll answer. Can
    you really think this is topical in comp.lang.c?

    --
    Ben.

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  • From Richard Damon@21:1/5 to Chris M. Thomasson on Mon Jul 8 19:34:02 2024
    On 7/8/24 6:17 PM, Chris M. Thomasson wrote:
    Are there "more" complex numbers than reals? It seems so, every real has
    its y, or imaginary, component set to zero. Therefore for each real
    there is an infinity of infinite embedding's for it wrt any real with a non-zero y axis? Fair enough, or really dumb? A little stupid? What do
    you think?

    In comp.lang.c the answer is yes, for if we assume the standard 8 byte
    floating point numbers, there are approximatly 2^64 possible reals
    (slightly less because the encoding is not totally exhaustive) but approximately 2^128 possible complex numbers.

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  • From Lawrence D'Oliveiro@21:1/5 to Chris M. Thomasson on Mon Jul 8 23:45:06 2024
    On Mon, 8 Jul 2024 15:17:29 -0700, Chris M. Thomasson wrote:

    Are there "more" complex numbers than reals?

    If you talking about the theoretical mathematical sets, then the answer is
    no. They can be mapped 1:1.

    An obvious way to do it is to interleave the digits of the real and
    imaginary parts to create a real.

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  • From James Kuyper@21:1/5 to Ben Bacarisse on Mon Jul 8 19:32:39 2024
    On 7/8/24 18:59, Ben Bacarisse wrote:
    "Chris M. Thomasson" <[email protected]> writes:

    Are there "more" complex numbers than reals?

    If you ask this in an appropriate group (sci.math?) I'll answer. Can
    you really think this is topical in comp.lang.c?

    I haven't seen more of Chris's message than what you've quoted. In the
    context of C, it's a easy (even trivial) question to answer.

    "Each complex type has the same representation and alignment
    requirements as an array type containing exactly two elements of the corresponding real type; the first element is equal to the real part,
    and the second element to the imaginary part, of the complex number." (6.2.5p17).

    Therefore, the number of different complex numbers that can be
    represented is therefore the square of the number of different numbers
    that can be represented in the corresponding real type.

    The corresponding question suitable for sci.math is much trickier to answer.

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  • From Tim Rentsch@21:1/5 to James Kuyper on Mon Jul 8 18:56:34 2024
    James Kuyper <[email protected]> writes:

    On 7/8/24 18:59, Ben Bacarisse wrote:

    "Chris M. Thomasson" <[email protected]> writes:

    Are there "more" complex numbers than reals?

    If you ask this in an appropriate group (sci.math?) I'll answer. Can
    you really think this is topical in comp.lang.c?

    I haven't seen more of Chris's message than what you've quoted. In the context of C, it's a easy (even trivial) question to answer.

    "Each complex type has the same representation and alignment
    requirements as an array type containing exactly two elements of the corresponding real type; the first element is equal to the real part,
    and the second element to the imaginary part, of the complex number." (6.2.5p17).

    Therefore, the number of different complex numbers that can be
    represented is therefore the square of the number of different numbers
    that can be represented in the corresponding real type.

    The answer is still no, because the question is about complex
    numbers and real numbers, not representable values.

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  • From Kaz Kylheku@21:1/5 to Chris M. Thomasson on Tue Jul 9 02:25:40 2024
    On 2024-07-08, Chris M. Thomasson <[email protected]> wrote:
    Are there "more" complex numbers than reals? It seems so, every real has
    its y, or imaginary, component set to zero. Therefore for each real
    there is an infinity of infinite embedding's for it wrt any real with a non-zero y axis? Fair enough, or really dumb? A little stupid? What do
    you think?

    The argument is not that simple. If we restrict to just integer complex
    numbers like 4 + 5i, then no; there aren't more of these than integers.
    Yet the same argument about axes and embeddings could be wrongly applied.

    Integer complex numbers are countable: you can start at 0, and then go
    in a spiral fashion: 1, 1 + i, i, -1 + i -1, ... thus they can be put
    into correspondendce with the natural numbers.

    --
    TXR Programming Language: http://nongnu.org/txr
    Cygnal: Cygwin Native Application Library: http://kylheku.com/cygnal
    Mastodon: @[email protected]

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  • From Kaz Kylheku@21:1/5 to Ben Bacarisse on Tue Jul 9 02:19:50 2024
    On 2024-07-08, Ben Bacarisse <[email protected]> wrote:
    "Chris M. Thomasson" <[email protected]> writes:

    Are there "more" complex numbers than reals?

    If you ask this in an appropriate group (sci.math?) I'll answer. Can
    you really think this is topical in comp.lang.c?

    It can be. There are clearly more complex doubles than
    there are doubles.

    --
    TXR Programming Language: http://nongnu.org/txr
    Cygnal: Cygwin Native Application Library: http://kylheku.com/cygnal
    Mastodon: @[email protected]

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  • From Blue-Maned_Hawk@21:1/5 to Chris M. Thomasson on Tue Jul 9 08:33:51 2024
    Chris M. Thomasson wrote:

    Are there "more" complex numbers than reals? It seems so, every real has
    its y, or imaginary, component set to zero. Therefore for each real
    there is an infinity of infinite embedding's for it wrt any real with a non-zero y axis? Fair enough, or really dumb? A little stupid? What do
    you think?

    No. You could draw a Hilbert curve (or any other space-filling curve) on
    a square of the complex plane and then tile it around in a spiral to fill
    up the rest of the plane. Then, you connect up all the ends of those
    tiles together and pull on the ends of the curve to stretch it out to form
    a line that is as infinite as the real number line.



    --
    Blue-Maned_Hawk│shortens to Hawk│/blu.mɛin.dʰak/│he/him/his/himself/Mr. blue-maned_hawk.srht.site
    A complex plane is what's used to fly to imaginary worlds.

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  • From Ben Bacarisse@21:1/5 to Kaz Kylheku on Tue Jul 9 10:04:13 2024
    Kaz Kylheku <[email protected]> writes:

    On 2024-07-08, Ben Bacarisse <[email protected]> wrote:
    "Chris M. Thomasson" <[email protected]> writes:

    Are there "more" complex numbers than reals?

    If you ask this in an appropriate group (sci.math?) I'll answer. Can
    you really think this is topical in comp.lang.c?

    It can be. There are clearly more complex doubles than
    there are doubles.

    Oh come on. If the question was about C representations, why did Chris
    put "more" in scare quotes? It's disingenuous to answer as if that was
    the intent without first asking what Christ meant by "more" (rather than
    just more).

    --
    Ben.

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  • From Kaz Kylheku@21:1/5 to Chris M. Thomasson on Tue Jul 9 08:47:24 2024
    On 2024-07-09, Chris M. Thomasson <[email protected]> wrote:
    On 7/8/2024 3:59 PM, Ben Bacarisse wrote:
    "Chris M. Thomasson" <[email protected]> writes:

    Are there "more" complex numbers than reals?

    If you ask this in an appropriate group (sci.math?) I'll answer. Can
    you really think this is topical in comp.lang.c?


    Ahhhh shit! this was meant for sci.math! Damn it! Cursing, ..., ..., .....

    Anyway, a complex number is a + ib where a and b are real.

    We can take any two reals (wlog, in the range [0, 1)):

    a = 0 . a0 a1 a2 a3 a4 .... (a0 a1 ... are decimal digits of a)

    b = 0 . b0 b1 b2 b3 b4 ....

    and intertwine the digits to make a new real number:

    c = 0. a0 b0 a1 b1 a2 b2 ...

    That new number c is still among the reals.

    The intertwining is undoable: you can recover the original pair
    of numbers by taking the even or odd digits.

    Thus, any complex number can be encoded as a real number,
    which implies that there can't be more of them than reals.

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  • From Richard Harnden@21:1/5 to All on Tue Jul 9 11:27:04 2024
    On 09/07/2024 1

    put "more" in scare quotes? It's disingenuous to answer as if that was
    the intent without first asking what Christ meant by "more" (rather than
    just more).


    Fish? Bread? Maybe Wine?

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  • From Ben Bacarisse@21:1/5 to Richard Harnden on Tue Jul 9 13:20:55 2024
    Richard Harnden <[email protected]d> writes:

    On 09/07/2024 1

    put "more" in scare quotes? It's disingenuous to answer as if that was
    the intent without first asking what Christ meant by "more" (rather than
    just more).


    Fish? Bread? Maybe Wine?

    Ha! An unusual typo for me. Given the way I see words, I had to read
    it quite a few times before I saw it, even with your comment.

    --
    Ben.

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  • From James Kuyper@21:1/5 to Ben Bacarisse on Tue Jul 9 11:49:33 2024
    On 7/9/24 05:04, Ben Bacarisse wrote:
    Kaz Kylheku <[email protected]> writes:

    On 2024-07-08, Ben Bacarisse <[email protected]> wrote:
    "Chris M. Thomasson" <[email protected]> writes:

    Are there "more" complex numbers than reals?

    If you ask this in an appropriate group (sci.math?) I'll answer. Can
    you really think this is topical in comp.lang.c?

    It can be. There are clearly more complex doubles than
    there are doubles.

    Oh come on. If the question was about C representations, why did Chris
    put "more" in scare quotes? It's disingenuous to answer as if that was
    the intent without first asking what Christ meant by "more" (rather than
    just more).

    It may be disingenuous, but deliberately misinterpreting his question as
    if it had been one that would be on-topic in this newgroup is an
    entirely appropriate way of reminding him that his question was off-topic.

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  • From Lawrence D'Oliveiro@21:1/5 to Chris M. Thomasson on Wed Jul 10 00:53:19 2024
    On Tue, 9 Jul 2024 12:00:29 -0700, Chris M. Thomasson wrote:

    By the way, did you take a look at my "fun"
    experiment wrt storing data in the roots of complex numbers?

    You can encode messages in anything.

    #!/usr/bin/python3

    import sys

    charset = ' .Hadefghilmnoprstwx'
    modulo = 23
    s = 1193321429126088671017703197607273471738040746714878246039040663141374779777444615292185709614467374016367591074170680369683264762098941
    num = iter(range(2, 9999))
    while s != 1 :
    n = next(num)
    if s % n == 0 :
    sys.stdout.write("%s" % charset[(n - 1) % modulo])
    s //= n
    #end if
    #end while
    sys.stdout.write("\n")

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  • From Lawrence D'Oliveiro@21:1/5 to Chris M. Thomasson on Thu Jul 11 01:59:20 2024
    On Wed, 10 Jul 2024 15:42:14 -0700, Chris M. Thomasson wrote:

    Integer complex numbers ...

    Another fun thing about integer complex numbers is that some numbers that
    are primes if you stay on the real line, become non-prime if complex
    integer factors are allowed.

    E.g.

    5 = (2 + i)(2 - i)
    29 = (5 + 2i)(5 - 2i)
    101 = (10 + i)(10 - i)

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