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xkcd: Day Counter

Started byLynn McGuire <lynnmcguire5@gmail.com>
First post2026-04-03 22:40 -0500
Last post2026-04-06 14:40 +0000
Articles 20 — 14 participants

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Contents

  xkcd: Day Counter Lynn McGuire <lynnmcguire5@gmail.com> - 2026-04-03 22:40 -0500
    Re: xkcd: Day Counter Your Name <YourName@YourISP.com> - 2026-04-04 16:46 +1300
      Re: xkcd: Day Counter Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-04-04 07:40 +0000
        Re: xkcd: Day Counter Nioclás Pól Caileán de Ghloucester <thanks-to@Taf.com> - 2026-04-04 16:19 +0000
      Re: xkcd: Day Counter Paul S Person <psperson@old.netcom.invalid> - 2026-04-04 09:16 -0700
      Re: xkcd: Day Counter Stuart Redmann <DerTopper@web.de> - 2026-04-06 16:10 +0200
        Re: xkcd: Day Counter Paul S Person <psperson@old.netcom.invalid> - 2026-04-06 08:33 -0700
    Re: xkcd: Day Counter R Daneel Olivaw <Danni@hyperspace.vogon.gov.invalid> - 2026-04-04 10:55 +0200
      Re: xkcd: Day Counter Paul S Person <psperson@old.netcom.invalid> - 2026-04-04 09:25 -0700
      Re: xkcd: Day Counter Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-04-04 22:21 +0000
    Re: xkcd: Day Counter Tony Nance <tnusenet17@gmail.com> - 2026-04-04 10:40 -0400
      Re: xkcd: Day Counter Mark Jackson <mjackson@alumni.caltech.edu> - 2026-04-04 11:01 -0400
    Re: xkcd: Day Counter Jay Morris <morrisj@epsilon3.me> - 2026-04-04 11:44 -0500
    Re: xkcd: Day Counter Chris Ahlstrom <OFeem1987@teleworm.us> - 2026-04-05 10:22 -0400
      Re: xkcd: Day Counter Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-05 14:13 -0700
        Re: xkcd: Day Counter Thomas Koenig <tkoenig@netcologne.de> - 2026-04-06 05:25 +0000
          Re: xkcd: Day Counter Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-06 00:43 -0700
            Re: xkcd: Day Counter Thomas Koenig <tkoenig@netcologne.de> - 2026-04-06 20:14 +0000
              Re: xkcd: Day Counter Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-04-06 14:30 -0700
    Re: xkcd: Day Counter candycanearter07 <candycanearter07@candycanearter07.nomail.afraid> - 2026-04-06 14:40 +0000

#655758 — xkcd: Day Counter

FromLynn McGuire <lynnmcguire5@gmail.com>
Date2026-04-03 22:40 -0500
Subjectxkcd: Day Counter
Message-ID<10qq170$d49s$2@dont-email.me>
xkcd: Day Counter
    https://xkcd.com/3228/

Yes, floating point errors are the bane of my life !  Not so much now 
with double precision but the single precision days were nightmares.

Explained at:
    https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter

Whatever you do, do not select “Space Opera Mode” in the new mode drop 
down list.  "Boat mode" made me a little queasy after a while.  And 
"modem mode" does not seem to do anything.

Lynn

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#655760

FromYour Name <YourName@YourISP.com>
Date2026-04-04 16:46 +1300
Message-ID<10qq1jh$dcph$1@dont-email.me>
In reply to#655758
On 2026-04-04 03:40:15 +0000, Lynn McGuire said:
> 
> xkcd: Day Counter
>     https://xkcd.com/3228/
> 
> Yes, floating point errors are the bane of my life !  Not so much now 
> with double precision but the single precision days were nightmares.
> 
> Explained at:
>     https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter
> 
> Whatever you do, do not select “Space Opera Mode” in the new mode 
> drop down list.  "Boat mode" made me a little queasy after a while.  
> And "modem mode" does not seem to do anything.
> 
> Lynn

Yep. It's a problem in Excel (still today!), which is relied on by 
almost all businesses, thanks to the idiots at Microsoft not being able 
to actually program. I discovered it by accident when I had some 
cross-checking calucations that said there was an error, when, after 
quite a lot of time trying to find the error, turned out to in Excel 
itself.  :-\

Those of us with brains use Apple computers and the Numbers spreadsheet 
program does not have this issue.

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#655767

FromLawrence D’Oliveiro <ldo@nz.invalid>
Date2026-04-04 07:40 +0000
Message-ID<10qqf90$gkpg$1@dont-email.me>
In reply to#655760
On Sat, 4 Apr 2026 16:46:58 +1300, Your Name wrote:

> Those of us with brains use Apple computers and the Numbers
> spreadsheet program does not have this issue.

Those of us with brains know how to use decimal or binary arithmetic
as appropriate to the problem at hand.

LibreOffice Calc:

    = 0.1 + 0.1 + 0.1 - 0.3

evaluates to

    0

Python, binary arithmetic:

    0.1 + 0.1 + 0.1 - 0.3

evaluates to

    5.551115123125783e-17

Python, decimal arithmetic:

    >>> import decimal; D = decimal.Decimal
    >>> D("0.1") + D("0.1") + D("0.1") - D("0.3")

evaluates to

    Decimal('0.0')

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#655782

FromNioclás Pól Caileán de Ghloucester <thanks-to@Taf.com>
Date2026-04-04 16:19 +0000
Message-ID<10qrdmt$18htl$2@paganini.bofh.team>
In reply to#655767
LibreOffice Draw and LibreOffice Writer are buggy.
(S. HTTP://Gloucester.Insomnia247.NL/ fuer Kontaktdaten!)

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#655783

FromPaul S Person <psperson@old.netcom.invalid>
Date2026-04-04 09:16 -0700
Message-ID<l4e2tkh3a4l2bmuqa79cq98tnhs9i70sm2@4ax.com>
In reply to#655760
On Sat, 4 Apr 2026 16:46:58 +1300, Your Name <YourName@YourISP.com>
wrote:

>On 2026-04-04 03:40:15 +0000, Lynn McGuire said:
>> 
>> xkcd: Day Counter
>>     https://xkcd.com/3228/
>> 
>> Yes, floating point errors are the bane of my life !  Not so much now 
>> with double precision but the single precision days were nightmares.
>> 
>> Explained at:
>>     https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter
>> 
>> Whatever you do, do not select “Space Opera Mode� in the new mode 
>> drop down list.  "Boat mode" made me a little queasy after a while.  
>> And "modem mode" does not seem to do anything.
>> 
>> Lynn
>
>Yep. It's a problem in Excel (still today!), which is relied on by 
>almost all businesses, thanks to the idiots at Microsoft not being able 
>to actually program. I discovered it by accident when I had some 
>cross-checking calucations that said there was an error, when, after 
>quite a lot of time trying to find the error, turned out to in Excel 
>itself.  :-\

In OOo, use of round(<value>;2) (or equivalent function and desired
precision) can help a lot.

>Those of us with brains use Apple computers and the Numbers spreadsheet 
>program does not have this issue.
-- 
"Here lies the Tuscan poet Aretino,
Who evil spoke of everyone but God,
Giving as his excuse, 'I never knew him.'"

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#655832

FromStuart Redmann <DerTopper@web.de>
Date2026-04-06 16:10 +0200
Message-ID<2081810922.796969382.868060.DerTopper-web.de@news.eternal-september.org>
In reply to#655760
Your Name <YourName@YourISP.com> wrote:
> On 2026-04-04 03:40:15 +0000, Lynn McGuire said:
>> 
>> xkcd: Day Counter
>> https://xkcd.com/3228/
>> 
>> Yes, floating point errors are the bane of my life !  Not so much now 
>> with double precision but the single precision days were nightmares.
>> 
>> Explained at:
>> https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter
>> 
>> Whatever you do, do not select “Space Opera Mode” in the new mode 
>> drop down list.  "Boat mode" made me a little queasy after a while.  
>> And "modem mode" does not seem to do anything.
>> 
>> Lynn
> 
> Yep. It's a problem in Excel (still today!), which is relied on by 
> almost all businesses, thanks to the idiots at Microsoft not being able 
> to actually program. I discovered it by accident when I had some 
> cross-checking calucations that said there was an error, when, after 
> quite a lot of time trying to find the error, turned out to in Excel 
> itself.  :-\
> 
> Those of us with brains use Apple computers and the Numbers spreadsheet 
> program does not have this issue.

I encountered the following problem with Excel: if you use Excel’s
Automation API (based on the Microsoft COM framework), you can access
everything inside an Excel workbook programmatically. Also any charts that
have been added to a spreadsheet. However, if you‘re trying to iterate
through the series of the graph and try to access the formatting of the
series (are there lines between the points of the series, if so which
color, thickness, etc.), you‘ll get an error when you’re accessing a series
that is not shown in the legend of the chart because the legend is too
small. If you increase the size of the chart to an ridiculous amount (so
that you can be sure that the legend will be big enough to show every
series of the chart), you can access everything without a problem. 

If a program contains such incredible errors, I would keep my fingers from
it. Although I haven’t tried to do the same thing with Open/LibreOffice‘s
automation API, I‘d vouch that such an error would not occur.

And yes, us professionals prefer Apple over MS, even though Visual Studio
has some features that I sorely miss in other IDEs.

Regards
Stuart

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#655839

FromPaul S Person <psperson@old.netcom.invalid>
Date2026-04-06 08:33 -0700
Message-ID<bgk7tk1c7chi06sv9qh3duep15klh6c0ir@4ax.com>
In reply to#655832
On Mon, 6 Apr 2026 16:10:08 +0200, Stuart Redmann <DerTopper@web.de>
wrote:

>Your Name <YourName@YourISP.com> wrote:
>> On 2026-04-04 03:40:15 +0000, Lynn McGuire said:
>>> 
>>> xkcd: Day Counter
>>> https://xkcd.com/3228/
>>> 
>>> Yes, floating point errors are the bane of my life !  Not so much now 
>>> with double precision but the single precision days were nightmares.
>>> 
>>> Explained at:
>>> https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter
>>> 
>>> Whatever you do, do not select â??Space Opera Modeâ?? in the new mode 
>>> drop down list.  "Boat mode" made me a little queasy after a while.  
>>> And "modem mode" does not seem to do anything.
>>> 
>>> Lynn
>> 
>> Yep. It's a problem in Excel (still today!), which is relied on by 
>> almost all businesses, thanks to the idiots at Microsoft not being able 
>> to actually program. I discovered it by accident when I had some 
>> cross-checking calucations that said there was an error, when, after 
>> quite a lot of time trying to find the error, turned out to in Excel 
>> itself.  :-\
>> 
>> Those of us with brains use Apple computers and the Numbers spreadsheet 
>> program does not have this issue.
>
>I encountered the following problem with Excel: if you use Excel’s
>Automation API (based on the Microsoft COM framework), you can access
>everything inside an Excel workbook programmatically. Also any charts that
>have been added to a spreadsheet. However, if you‘re trying to iterate
>through the series of the graph and try to access the formatting of the
>series (are there lines between the points of the series, if so which
>color, thickness, etc.), you‘ll get an error when you’re accessing a series
>that is not shown in the legend of the chart because the legend is too
>small. If you increase the size of the chart to an ridiculous amount (so
>that you can be sure that the legend will be big enough to show every
>series of the chart), you can access everything without a problem. 
>
>If a program contains such incredible errors, I would keep my fingers from
>it. Although I haven’t tried to do the same thing with Open/LibreOffice‘s
>automation API, I‘d vouch that such an error would not occur.

Theoretically speaking, would that allow creating a program that can
convert an ODT file containing bits of spreadsheet (copied and pasted
from an ODS file) to a text file that actually includes the spreasheet
bits instead of ignoring them?

>And yes, us professionals prefer Apple over MS, even though Visual Studio
>has some features that I sorely miss in other IDEs.
-- 
"Here lies the Tuscan poet Aretino,
Who evil spoke of everyone but God,
Giving as his excuse, 'I never knew him.'"

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#655769

FromR Daneel Olivaw <Danni@hyperspace.vogon.gov.invalid>
Date2026-04-04 10:55 +0200
Message-ID<10qqjmj$16me1$1@paganini.bofh.team>
In reply to#655758
Lynn McGuire wrote:
> xkcd: Day Counter
>     https://xkcd.com/3228/
> 
> Yes, floating point errors are the bane of my life !  Not so much now 
> with double precision but the single precision days were nightmares.
> 
> Explained at:
>     https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter
> 
> Whatever you do, do not select “Space Opera Mode” in the new mode drop 
> down list.  "Boat mode" made me a little queasy after a while.  And 
> "modem mode" does not seem to do anything.
> 
> Lynn
> 

The point about "modem mode" is that everything is painfully s-l-o-w. 
My browser (Firefox) informed me that a script was slowing my machine 
down (processor utilisation showed that!) and did I want to stop it?
I did.
Darkest Mode was amusing
Space Opera Mode was a problem.
Screensaver Mode was fun.

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#655787

FromPaul S Person <psperson@old.netcom.invalid>
Date2026-04-04 09:25 -0700
Message-ID<pee2tkdegbuuabrnencsh022fhsfl26rd1@4ax.com>
In reply to#655769
On Sat, 4 Apr 2026 10:55:47 +0200, R Daneel Olivaw
<Danni@hyperspace.vogon.gov.invalid> wrote:

>Lynn McGuire wrote:
>> xkcd: Day Counter
>>     https://xkcd.com/3228/
>> 
>> Yes, floating point errors are the bane of my life !  Not so much now 
>> with double precision but the single precision days were nightmares.
>> 
>> Explained at:
>>     https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter
>> 
>> Whatever you do, do not select “Space Opera Mode” in the new mode drop 
>> down list.  "Boat mode" made me a little queasy after a while.  And 
>> "modem mode" does not seem to do anything.
>
>The point about "modem mode" is that everything is painfully s-l-o-w. 
>My browser (Firefox) informed me that a script was slowing my machine 
>down (processor utilisation showed that!) and did I want to stop it?
>I did.

Here, on my Coolby Laptop, it just draws it "line by line" from top to
bottom. Not really slow, and certainly not painful. In Edge. CPU usage
did go from 9% to 60% (actually, it varied between 20% or so and
higher values, with short peaks at 60%). 

But I'm not surprised. The Coolby Laptop is so much faster than the HP
Envy desktop that it was purchased to provide enough functionality to
keep going until a new replacement desktop computer was found that I
gave up on the new desktop idea and am using the Coolby Laptop as my
main computer.

>Darkest Mode was amusing
>Space Opera Mode was a problem.
>Screensaver Mode was fun.

Indeed.
Stained Glass Mode and Airplane Mode were also interesting.
-- 
"Here lies the Tuscan poet Aretino,
Who evil spoke of everyone but God,
Giving as his excuse, 'I never knew him.'"

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#655800

FromLawrence D’Oliveiro <ldo@nz.invalid>
Date2026-04-04 22:21 +0000
Message-ID<10qs2sv$10uoq$6@dont-email.me>
In reply to#655769
On Sat, 4 Apr 2026 10:55:47 +0200, R Daneel Olivaw wrote:

> My browser (Firefox) informed me that a script was slowing my
> machine down (processor utilisation showed that!) and did I want to
> stop it? I did.

Sounds like they were using a suboptimal way of slowing down the
display, by hogging the main thread for that page or something dumb
like that.

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#655773

FromTony Nance <tnusenet17@gmail.com>
Date2026-04-04 10:40 -0400
Message-ID<10qr7t6$ojmo$1@dont-email.me>
In reply to#655758
On 4/3/26 11:40 PM, Lynn McGuire wrote:
> xkcd: Day Counter
>     https://xkcd.com/3228/
> 
> Yes, floating point errors are the bane of my life !  Not so much now 
> with double precision but the single precision days were nightmares.
> 
> Explained at:
>     https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter
> 
> Whatever you do, do not select “Space Opera Mode” in the new mode drop 
> down list.  


But if you do select Space Opera Mode, the box to change modes is active 
as it scrolls by. And the rollover text still works too.

Tony



"Boat mode" made me a little queasy after a while.  And
> "modem mode" does not seem to do anything.
> 
> Lynn
> 

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#655776

FromMark Jackson <mjackson@alumni.caltech.edu>
Date2026-04-04 11:01 -0400
Message-ID<n3cnecFs5t7U2@mid.individual.net>
In reply to#655773
On 4/4/2026 10:40 AM, Tony Nance wrote:
> On 4/3/26 11:40 PM, Lynn McGuire wrote:
>> xkcd: Day Counter
>>     https://xkcd.com/3228/
>>
>> Yes, floating point errors are the bane of my life !  Not so much now 
>> with double precision but the single precision days were nightmares.
>>
>> Explained at:
>>     https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter
>>
>> Whatever you do, do not select “Space Opera Mode” in the new mode drop 
>> down list. 
> 
> 
> But if you do select Space Opera Mode, the box to change modes is active 
> as it scrolls by.

And if you let it get too "far away," the scrollwheel on your mouse can 
bring it back.  Not a problem at all.

-- 
Mark Jackson - https://mark-jackson.online/
   I think it's a mistake — a very tempting mistake to make —
   to take stock by looking at what we still have rather than
   what we have already lost.   - M. Gessen

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#655788

FromJay Morris <morrisj@epsilon3.me>
Date2026-04-04 11:44 -0500
Message-ID<10qrf4r$r22r$1@epsilon3.eternal-september.org>
In reply to#655758
On 4/3/2026 10:40 PM, Lynn McGuire wrote:
> xkcd: Day Counter
>     https://xkcd.com/3228/
> 
> Yes, floating point errors are the bane of my life !  Not so much now 
> with double precision but the single precision days were nightmares.
> 
> Explained at:
>     https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter
> 
> Whatever you do, do not select “Space Opera Mode” in the new mode drop 
> down list.  "Boat mode" made me a little queasy after a while.  And 
> "modem mode" does not seem to do anything.
> 
> Lynn
> 

When I selected modem mode it made the appropriate noises and the 
picture slowly displayed as it downloaded.

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#655811

FromChris Ahlstrom <OFeem1987@teleworm.us>
Date2026-04-05 10:22 -0400
Message-ID<10qtr82$1f4di$2@dont-email.me>
In reply to#655758
Lynn McGuire wrote this screed in ALL-CAPS:

> xkcd: Day Counter
>     https://xkcd.com/3228/
>
> Yes, floating point errors are the bane of my life !  Not so much now 
> with double precision but the single precision days were nightmares.

Well these days we have long double.

> Explained at:
>     https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter
>
> Whatever you do, do not select “Space Opera Mode” in the new mode drop 
> down list.  "Boat mode" made me a little queasy after a while.  And 
> "modem mode" does not seem to do anything.

Took me a little while to figure out where the mode dropdown was
when in Origami mode.

-- 
"One day I woke up and discovered that I was in love with tripe."
		-- Tom Anderson

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#655818

FromKeith Thompson <Keith.S.Thompson+u@gmail.com>
Date2026-04-05 14:13 -0700
Message-ID<87mrzhp0tt.fsf@example.invalid>
In reply to#655811
Chris Ahlstrom <OFeem1987@teleworm.us> writes:
> Lynn McGuire wrote this screed in ALL-CAPS:
>
>> xkcd: Day Counter
>>     https://xkcd.com/3228/
>>
>> Yes, floating point errors are the bane of my life !  Not so much now 
>> with double precision but the single precision days were nightmares.
>
> Well these days we have long double.

C has had long double as a standard type since the original 1989
ANSI C standard.  (K&R1, 1978, didn't have long double.)

But wider floating-point types don't eliminate rounding errors.

[...]

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

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#655822

FromThomas Koenig <tkoenig@netcologne.de>
Date2026-04-06 05:25 +0000
Message-ID<10qvg49$1t2f3$2@dont-email.me>
In reply to#655818
Keith Thompson <Keith.S.Thompson+u@gmail.com> schrieb:
> Chris Ahlstrom <OFeem1987@teleworm.us> writes:
>> Lynn McGuire wrote this screed in ALL-CAPS:
>>
>>> xkcd: Day Counter
>>>     https://xkcd.com/3228/
>>>
>>> Yes, floating point errors are the bane of my life !  Not so much now 
>>> with double precision but the single precision days were nightmares.
>>
>> Well these days we have long double.
>
> C has had long double as a standard type since the original 1989
> ANSI C standard.  (K&R1, 1978, didn't have long double.)
>
> But wider floating-point types don't eliminate rounding errors.

Nor does "long double" have to be any more accurate thean
"double".  C's type system leaves something to be desired
in that respect.

Fortran showed how it's done with its kind numbers and
SELECTED_REAL_KIND function - you ask for a certain minimum
precision, and the compiler either gives it to you, or your program
fails at compile time.

-- 
This USENET posting was made without artificial intelligence,
artificial impertinence, artificial arrogance, artificial stupidity,
artificial flavorings or artificial colorants.

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#655827

FromKeith Thompson <Keith.S.Thompson+u@gmail.com>
Date2026-04-06 00:43 -0700
Message-ID<87bjfw4jq5.fsf@example.invalid>
In reply to#655822
Thomas Koenig <tkoenig@netcologne.de> writes:
> Keith Thompson <Keith.S.Thompson+u@gmail.com> schrieb:
>> Chris Ahlstrom <OFeem1987@teleworm.us> writes:
>>> Lynn McGuire wrote this screed in ALL-CAPS:
>>>> xkcd: Day Counter
>>>>     https://xkcd.com/3228/
>>>>
>>>> Yes, floating point errors are the bane of my life !  Not so much now 
>>>> with double precision but the single precision days were nightmares.
>>>
>>> Well these days we have long double.
>>
>> C has had long double as a standard type since the original 1989
>> ANSI C standard.  (K&R1, 1978, didn't have long double.)
>>
>> But wider floating-point types don't eliminate rounding errors.
>
> Nor does "long double" have to be any more accurate thean
> "double".  C's type system leaves something to be desired
> in that respect.
>
> Fortran showed how it's done with its kind numbers and
> SELECTED_REAL_KIND function - you ask for a certain minimum
> precision, and the compiler either gives it to you, or your program
> fails at compile time.

You can do the same thing in C or C++ with a compile-time test.

#include <float.h>

#if LDBL_DIG < 18
#error "long double doesn't have enough precision"
#endif

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

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#655850

FromThomas Koenig <tkoenig@netcologne.de>
Date2026-04-06 20:14 +0000
Message-ID<10r147c$2c38c$1@dont-email.me>
In reply to#655827
Keith Thompson <Keith.S.Thompson+u@gmail.com> schrieb:
> Thomas Koenig <tkoenig@netcologne.de> writes:
>> Keith Thompson <Keith.S.Thompson+u@gmail.com> schrieb:
>>> Chris Ahlstrom <OFeem1987@teleworm.us> writes:
>>>> Lynn McGuire wrote this screed in ALL-CAPS:
>>>>> xkcd: Day Counter
>>>>>     https://xkcd.com/3228/
>>>>>
>>>>> Yes, floating point errors are the bane of my life !  Not so much now 
>>>>> with double precision but the single precision days were nightmares.
>>>>
>>>> Well these days we have long double.
>>>
>>> C has had long double as a standard type since the original 1989
>>> ANSI C standard.  (K&R1, 1978, didn't have long double.)
>>>
>>> But wider floating-point types don't eliminate rounding errors.
>>
>> Nor does "long double" have to be any more accurate thean
>> "double".  C's type system leaves something to be desired
>> in that respect.
>>
>> Fortran showed how it's done with its kind numbers and
>> SELECTED_REAL_KIND function - you ask for a certain minimum
>> precision, and the compiler either gives it to you, or your program
>> fails at compile time.
>
> You can do the same thing in C or C++ with a compile-time test.
>
>#include <float.h>
>
>#if LDBL_DIG < 18
>#error "long double doesn't have enough precision"
>#endif

Not quite the same.  SELECTED_REAL_KIND gives you the
_minimum_ real type for your requirements.

-- 
This USENET posting was made without artificial intelligence,
artificial impertinence, artificial arrogance, artificial stupidity,
artificial flavorings or artificial colorants.

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#655857

FromKeith Thompson <Keith.S.Thompson+u@gmail.com>
Date2026-04-06 14:30 -0700
Message-ID<8734174vzu.fsf@example.invalid>
In reply to#655850
Thomas Koenig <tkoenig@netcologne.de> writes:
> Keith Thompson <Keith.S.Thompson+u@gmail.com> schrieb:
>> Thomas Koenig <tkoenig@netcologne.de> writes:
[...]
>>> Fortran showed how it's done with its kind numbers and
>>> SELECTED_REAL_KIND function - you ask for a certain minimum
>>> precision, and the compiler either gives it to you, or your program
>>> fails at compile time.
>>
>> You can do the same thing in C or C++ with a compile-time test.
>>
>>#include <float.h>
>>
>>#if LDBL_DIG < 18
>>#error "long double doesn't have enough precision"
>>#endif
>
> Not quite the same.  SELECTED_REAL_KIND gives you the
> _minimum_ real type for your requirements.

You can do that in C or C++ too, though not as cleanly.  With a
series of #if directives, you can select the minimal floating-point
type (out of float, double, long double) that satisfies some
requirement.  But I don't recall ever seeing code that does this.

This is rapidly going off-topic for most of the newsgroups this is
posted to, so I won't go into more detail.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

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#655834

Fromcandycanearter07 <candycanearter07@candycanearter07.nomail.afraid>
Date2026-04-06 14:40 +0000
Message-ID<slrn10t7h7v.gdt2.candycanearter07@candydeb.host.invalid>
In reply to#655758
Lynn McGuire <lynnmcguire5@gmail.com> wrote at 03:40 this Saturday (GMT):
> xkcd: Day Counter
>     https://xkcd.com/3228/
>
> Yes, floating point errors are the bane of my life !  Not so much now 
> with double precision but the single precision days were nightmares.
>
> Explained at:
>     https://www.explainxkcd.com/wiki/index.php/3228:_Day_Counter
>
> Whatever you do, do not select “Space Opera Mode” in the new mode drop 
> down list.  "Boat mode" made me a little queasy after a while.  And 
> "modem mode" does not seem to do anything.
>
> Lynn


I think modem mode actually slows down the transfer rate, cute idea but
it freezes my browser. Boat Mode is pretty nostalgic tho, reminds me of
WaveHello :)
-- 
user <candycane> is generated from /dev/urandom

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