[ruby-core:37207] [Ruby 1.9 - Feature #4897][Open] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[ruby-core:37207] [Ruby 1.9 - Feature #4897][Open] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[Simon Baird]

Issue #4897 has been reported by Simon Baird.

----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
http://redmine.ruby-lang.org/issues/4897

Author: Simon Baird
Status: Open
Priority: Low
Assignee: 
Category: core
Target version: 1.9.x


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://redmine.ruby-lang.org

[ruby-core:37208] [Ruby 1.9 - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[Simon Baird]

Issue #4897 has been updated by Simon Baird.


Sorry for the too long title. Don't know how to edit. Suggested title: "Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi"
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
http://redmine.ruby-lang.org/issues/4897

Author: Simon Baird
Status: Open
Priority: Low
Assignee: 
Category: core
Target version: 1.9.x


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://redmine.ruby-lang.org

[ruby-core:37209] [Ruby 1.9 - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[Simon Baird]

Issue #4897 has been updated by Simon Baird.


"Direct link to gist":https://gist.github.com/1029552
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
http://redmine.ruby-lang.org/issues/4897

Author: Simon Baird
Status: Open
Priority: Low
Assignee: 
Category: core
Target version: 1.9.x


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://redmine.ruby-lang.org

[ruby-core:37210] [Ruby 1.9 - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[Simon Baird]

Issue #4897 has been updated by Simon Baird.


Clickable link to <a href="http://tauday.com/">http://tauday.com/</a>
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
http://redmine.ruby-lang.org/issues/4897

Author: Simon Baird
Status: Open
Priority: Low
Assignee: 
Category: core
Target version: 1.9.x


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://redmine.ruby-lang.org

[ruby-core:43636] [ruby-trunk - Feature #4897][Feedback] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[mame (Yusuke Endoh)]

Issue #4897 has been updated by mame (Yusuke Endoh).

Category changed from core to Joke
Status changed from Open to Feedback


----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-25136

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: 2.0.0


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:43639] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[duerst (Martin Dürst)]

Issue #4897 has been updated by duerst (Martin Dürst).


We have discussed this at today's developers' meeting in Akihabara.

We highly doubt that there are many mathematicians, physicists, engineers, and so on, who use τ. Once τ is widely accepted in these communities, we might add it.
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-25139

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: 2.0.0


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:43666] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[trans (Thomas Sawyer)]

Issue #4897 has been updated by trans (Thomas Sawyer).


I'm trying to get used to the idea of eating a pizza taue, myself. :-)

This is the classic chicken and egg situation -- "We'll do it if it's popular", but "It won't get popular unless people do it".

I think Tau=2*Pi is a good idea. So if it were just up to me, I'd add it just to show support. It's a rather tiny and harmless addition.
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-25168

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: 2.0.0


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:48355] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[ko1 (Koichi Sasada)]

Issue #4897 has been updated by ko1 (Koichi Sasada).

Target version changed from 2.0.0 to Next Major


----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-31664

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:52796] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[trans (Thomas Sawyer)]

Issue #4897 has been updated by trans (Thomas Sawyer).


Could these patch be applied now? As previously said, it's a good thing to show support for and it's a rather tiny and otherwise harmless addition.
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-36899

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:52878] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[sbaird (Simon Baird)]

Issue #4897 has been updated by sbaird (Simon Baird).


https://github.com/search?q=%22TAU+%3D+2+%2A+Math.PI%22&type=Code

https://github.com/search?q=%22TAU+%3D+PI+*+2%22&type=Code
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-36997

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:52928] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[nobu (Nobuyoshi Nakada)]

Issue #4897 has been updated by nobu (Nobuyoshi Nakada).


Why is it called as τ, half of π?
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37090

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:52932] Re: [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[Matthew Kerwin]

[-- Attachment #1: Type: text/plain, Size: 914 bytes --]

On 26 February 2013 19:20, nobu (Nobuyoshi Nakada) <nobu@ruby-lang.org>wrote:

>
> Why is it called as τ, half of π?
>

It's actually two of π.  The reason for the name is justified here:
http://tauday.com/tau-manifesto#sec:one_turn

In summary: tau is the first letter of the Greek word "tornos" (lathe),
which is the root of the English word "turn;" and the tau constant (2*PI)
is the ratio of a circle's radius to its circumference (i.e. one _turn_.)
Also "the horizontal line in each letter suggests that we interpret the
"legs" as _*denominators_*, so that π has two legs in its denominator,
while τ has only one. Seen this way, the relationship τ=2π is perfectly
natural."

-- 
  Matthew Kerwin, B.Sc (CompSci) (Hons)
  http://matthew.kerwin.net.au/
  ABN: 59-013-727-651

  "You'll never find a programming language that frees
  you from the burden of clarifying your ideas." - xkcd

[-- Attachment #2: Type: text/html, Size: 1557 bytes --]

[ruby-core:52933] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[phluid61 (Matthew Kerwin)]

Issue #4897 has been updated by phluid61 (Matthew Kerwin).


nobu (Nobuyoshi Nakada) wrote:
> Why is it called as τ, half of π?

It's actually two of π.  The reason for the name is justified here: http://tauday.com/tau-manifesto#sec:one_turn

In summary: tau is the first letter of the Greek word "tornos" (lathe), which is the root of the English word "turn;" and the tau constant (2*PI) is the ratio of a circle's radius to its circumference (i.e. one _turn_.)  Also "the horizontal line in each letter suggests that we interpret the “legs” as _denominators_, so that π has two legs in its denominator, while τ has only one. Seen this way, the relationship τ=2π is perfectly natural."
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37094

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:52969] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[Student (Nathan Zook)]

Issue #4897 has been updated by Student (Nathan Zook).


Please, just say no.  This garbage is one and only thing that has made me really glad that I decided to leave academia.  Having to dissuade every crank from this idea would ruin my mood for weeks.

There a large number of excellent candidate constants to be included.  There is absolutely no cause to include constants that are power-of-two multiples of each other.  You want tau in math?  Fine.  module Math ; TAU = 2 * PI ; end.  Done.  Put that in all your files.  Move it to your initialization code.  Publish a gem.  I don't care.  But don't waste the time of people who understand that shifting a binary point by 1 really isn't a big deal.

-Math::PI

----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37123

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:52980] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[bug (Harrison Reiser)]

Issue #4897 has been updated by bug (Harrison Reiser).


Wow, such vitriol !  I could point out a correlation between it and your stance on academia, but I would be flying in the face of not only courtesy but also the whole point of all this.  I assure you that tau is not a joke, and has everything to do with mere common sense, both in pedagogy and practice (which, as it were, seems to be what many have come to know Ruby for).

While, as you say, not having the full circle constant is "not a big deal" given a simple means to derive it, I would be shocked to learn that any practiced programmer makes use of pi alone more often than 2*pi.  For this very reason many libraries for other languages include both constants, not just for coding efficiency but for _runtime_ efficiency.  So far, this constant has almost ubiquitously been named TWO_PI (or some variation thereof) simply by convention, but the fact of its prevalence should be enough indication of its _independent usefulness_ (an important distinction, one which I have no intention of debating further, having already been, repeatedly and at length -- see https://en.wikipedia.org/wiki/User:Waldir/Tau for examples).

Now, dynamic languages such as Ruby and Python stand in a unique position.  As intuitiveness and coder efficiency are among their primary goals, they indeed have no reason to include a constant named TWO_PI, which would overall detract from these goals.  However, a constant named TAU would serve as an indication that this number has some distinction of its own, namely the aforementioned independent usefulness.  Therefore if it is to be included at all it should be with conviction rather than the attitude of mere quiet tolerance (as of a vocal minority), as it would indeed stand as a statement to the programming community.

The decision to postpone its addition until recognition spreads further is reasonable, but as trans mentioned it perpetuates the chicken and egg problem.  Either way, I hope I have raised sufficient objection to categorizing this issue as a "Joke".

-bug
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37131

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:52981] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[drbrain (Eric Hodel)]

Issue #4897 has been updated by drbrain (Eric Hodel).


=begin

Despite all the argument for this constant, nobody has provided a patch, so it seems like a joke.

Runtime performance of a constant lookup is 3% +/- 1.2% faster than multiplying a float by 2 on my machine over 20 million multiplications.  3% for a built-in constant doesn't seem like a big deal.

I don't trust a wikipedia user page as a reference, it doesn't go through the same vetting process as a regular wikipedia page.

Benchmarks:

  $ cat bm.rb 
  require 'benchmark'
  
  module Math
    TAU = 2*Math::PI
  end
  
  range = Float::EPSILON..10.0
  
  N = Integer ARGV.shift
  
  case ARGV.shift
  when 'tau' then
    puts Benchmark.measure {
      N.times do
        2 * Math::PI * rand(range)
      end
    }.real
  when '2pi' then
    puts Benchmark.measure {
      N.times do
        2 * Math::TAU * rand(range)
      end
    }.real
  else
    abort "#{$0} N tau|2pi"
  end
  $ for i in `jot 20`; do ruby bm.rb 1_000_000 2pi; done > 2pi.txt
  $ for i in `jot 20`; do ruby bm.rb 1_000_000 tau; done > tau.txt
  $ ministat tau.txt 2pi.txt 
  x tau.txt
  + 2pi.txt
  +------------------------------------------------------------------------------+
  |x    xx    x    +   +     +    +      +                                       |
  |x x x*xxx+ x * x+   * ++x +++  +     ++        +                             +|
  | |____M_A___|_|___________MA_______________|                                  |
  +------------------------------------------------------------------------------+
      N           Min           Max        Median           Avg        Stddev
  x  20      0.486589      0.504393      0.491397    0.49242015  0.0049904288
  +  20      0.490699      0.544828      0.506571     0.5073239   0.011828075
  Difference at 95.0% confidence
  	0.0149037 +/- 0.00581011
  	3.02663% +/- 1.17991%
  	(Student's t, pooled s = 0.00907766)  

=end
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37132

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:52982] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[trans (Thomas Sawyer)]

Issue #4897 has been updated by trans (Thomas Sawyer).


> Despite all the argument for this constant, nobody has provided a patch, so it seems like a joke.

"Here is a patch on trunk that implements this: http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html"


----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37133

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:52983] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[phluid61 (Matthew Kerwin)]

Issue #4897 has been updated by phluid61 (Matthew Kerwin).

File tau.patch added

drbrain (Eric Hodel) wrote:
> Despite all the argument for this constant, nobody has provided a patch, so it seems like a joke.

The gist linked in Comment 2 was a diff/patch, althought it's outdated and no longer applies cleanly.  I've attached a new patch (generated using `git diff`).  Please let me know if I'm supposed to generate it with --no-prefix
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37134

Author: sbaird (Simon Baird)
Status: Feedback
Priority: Low
Assignee: 
Category: Joke
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:52984] [ruby-trunk - Feature #4897][Assigned] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[drbrain (Eric Hodel)]

Issue #4897 has been updated by drbrain (Eric Hodel).

Status changed from Feedback to Assigned
Assignee set to matz (Yukihiro Matsumoto)

The patch is fine.
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37135

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: Joke
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:52986] Re: [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

["Martin J. Dürst"]

Hello Eric,

I'm confused by the code below. First, it uses Math::PI with the 'tau' 
option, and Math::TAU with the '2pi' option. Second, even when using 
Math::TAU, it includes a multiplication by 2.

Regards,   Martin.

On 2013/02/27 14:08, drbrain (Eric Hodel) wrote:

> Benchmarks:
>
>    $ cat bm.rb
>    require 'benchmark'
>
>    module Math
>      TAU = 2*Math::PI
>    end
>
>    range = Float::EPSILON..10.0
>
>    N = Integer ARGV.shift
>
>    case ARGV.shift
>    when 'tau' then
>      puts Benchmark.measure {
>        N.times do
>          2 * Math::PI * rand(range)
>        end
>      }.real
>    when '2pi' then
>      puts Benchmark.measure {
>        N.times do
>          2 * Math::TAU * rand(range)
>        end
>      }.real
>    else
>      abort "#{$0} N tau|2pi"
>    end

[ruby-core:53001] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[marcandre (Marc-Andre Lafortune)]

Issue #4897 has been updated by marcandre (Marc-Andre Lafortune).

Category changed from Joke to core

duerst (Martin Dürst) wrote:
> Hello Eric,
>  
>  Second, even when using 
>  Math::TAU, it includes a multiplication by 2.

Right, I'd say the test doesn't say much... Actually, any difference apparently measured has to be meaningless, there's to intrinsic difference in either cases.

For what it's worth:

require 'fruity'

module Math
  TAU = 2 * PI
end
compare do
  pi  { Math.cos(2 * Math::PI) }
  tau { Math.cos(Math::TAU) }
end
# => tau is faster than pi by 50.0% ± 10.0%

I had to call Math.cos, because otherwise just accessing Math::TAU is too difficult to time.

Math currently has 2 constants.
I don't see a huge downside in increasing this. On the other hand, TAU is so easy to calculate, I would trust that anyone knowing of it's existence would simply define it.
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37154

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:53004] Re: [ruby-trunk - Feature #4897][Assigned] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[David MacMahon]

I vote -1 on this idea because the name "TAU" is used in a number of fields to represent a wide variety of things:

http://en.wikipedia.org/wiki/Greek_letters_used_in_mathematics,_science,_and_engineering#.CE.A4.CF.84_.28tau.29

For example, tau as also used as a constant representing the golden ratio (1.618...).

The names "PI" and "E" are used far more consistently across fields.  Giving special preference to one (proposed!) use of the name "TAU" seems unfair to the other (established!) uses.

How about making a "twopi" gem that defines Math::TAU and BigMath.TAU?  If it is as useful as its proponents claim, it will undoubtedly become a very popular gem and the public outcry to add it to the core of the language will be deafening.

Dave

On Feb 26, 2013, at 9:54 PM, drbrain (Eric Hodel) wrote:

> 
> Issue #4897 has been updated by drbrain (Eric Hodel).
> 
> Status changed from Feedback to Assigned
> Assignee set to matz (Yukihiro Matsumoto)
> 
> The patch is fine.
> ----------------------------------------
> Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
> https://bugs.ruby-lang.org/issues/4897#change-37135
> 
> Author: sbaird (Simon Baird)
> Status: Assigned
> Priority: Low
> Assignee: matz (Yukihiro Matsumoto)
> Category: Joke
> Target version: Next Major
> 
> 
> Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.
> 
> Here is a patch on trunk that implements this:
> http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html
> 
> Allow me to anticipate and respond in advance to some common objections:
> 
> 1. It's easy to define it yourself so why put this in core.
> Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.
> 
> 2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
> The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.
> 
> 
> -- 
> http://bugs.ruby-lang.org/
> 

[ruby-core:53012] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[JosephLindenberg (Joseph Lindenberg)]

Issue #4897 has been updated by JosephLindenberg (Joseph Lindenberg).


The Processing programming language recently added TAU:
     http://code.google.com/p/processing/source/browse/trunk/processing/core/src/processing/core/PConstants.java

It does seem to be showing up more and more frequently.  Here's a recent SAMS book where the author uses it in his examples:
     http://books.google.com/books?id=BFda3Z71Y5YC&printsec=frontcover

I'm in favor of adding TAU.  It's definitely not the same as having a bunch of multiples and submultiples of a constant.  In fact, you really could say that right now, we have the submultiple-of-a-constant HALF_TAU, just under a different name.

----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37168

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:53013] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[phluid61 (Matthew Kerwin)]

Issue #4897 has been updated by phluid61 (Matthew Kerwin).

File tau.patch added

I just noticed a stupid typo in the patch I submitted. Sorry.
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37167

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:53014] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[JosephLindenberg (Joseph Lindenberg)]

Issue #4897 has been updated by JosephLindenberg (Joseph Lindenberg).


david_macmahon (David MacMahon) wrote:
>  For example, tau is also used as a constant representing the golden ratio (1.618...).

No, not anymore.  φ (phi) is used for that now.
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37169

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:53046] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[drbrain (Eric Hodel)]

Issue #4897 has been updated by drbrain (Eric Hodel).


=begin
Martin, you are right.  With a corrected benchmark there is an 8.5% +/- 1.2%:

  x tau.txt
  + 2pi.txt
  +--------------------------------------------------------------------------+
  |xx      x x                              + +      +     +                 |
  |xx x    xxxx x x           x    +  + + + + +++ +  + +  ++   + +          +|
  | |______A_____|                       |________MA_________|               |
  +--------------------------------------------------------------------------+
      N           Min           Max        Median           Avg        Stddev
  x  20      0.526745      0.557717      0.535967     0.5353094  0.0073255609
  +  20      0.562776       0.60921      0.579785     0.5810366   0.011508619
  Difference at 95.0% confidence
  	0.0457272 +/- 0.00617423
  	8.5422% +/- 1.15339%
  	(Student's t, pooled s = 0.00964656)

=end

----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37198

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:53047] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[alexeymuranov (Alexey Muranov)]

Issue #4897 has been updated by alexeymuranov (Alexey Muranov).


+1
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37199

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:53048] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[marcandre (Marc-Andre Lafortune)]

Issue #4897 has been updated by marcandre (Marc-Andre Lafortune).


drbrain (Eric Hodel) wrote:
> Martin, you are right.  With a corrected benchmark there is an 8.5% +/- 1.2% improvement:

To be more accurate, you'd have to subtract the time of an empty loop. If you compare 42 * pi with 42 *pi; 42 * pi using your technique, you won't get the expected answer (100%). I get ~50% with your technique.

I should introduce some of the techniques in ministat in my fruity gem.

----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37200

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:53053] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[sbaird (Simon Baird)]

Issue #4897 has been updated by sbaird (Simon Baird).


david_macmahon (David MacMahon) wrote:
>  I vote -1 on this idea because the name "TAU" is used in a number of fields to represent a wide variety of things:
>  For example, tau as also used as a constant representing the golden ratio (1.618...).
>  

mhartl addresses this here:
http://tauday.com/tau-manifesto#sec:ambiguous_notation
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37207

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:53054] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[sbaird (Simon Baird)]

Issue #4897 has been updated by sbaird (Simon Baird).


I don't think the benchmarks are particularly relevant here. We should define Tau because it's important, not for any performance benefit.
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37208

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:53066] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[Eregon (Benoit Daloze)]

Issue #4897 has been updated by Eregon (Benoit Daloze).


sbaird (Simon Baird) wrote:
> I don't think the benchmarks are particularly relevant here. We should define Tau because it's important, not for any performance benefit.

Indeed.

Although I am not sure of the importance of having TAU. One PI is fine for unit conversions as well as computing the area of a circle. But there are also many cases of 2*PI, which sounds less-than-ideal.
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-37220

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:54259] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[bug (Harrison Reiser)]

Issue #4897 has been updated by bug (Harrison Reiser).


Eregon (Benoit Daloze) wrote:
> Although I am not sure of the importance of having TAU. One PI is fine for unit conversions as well as computing the area of a circle. But there are also many cases of 2*PI, which sounds less-than-ideal.

They are more common than you would think.  Finding the area of circles is actually relatively specialized, in comparison with, for example, circular sectors (1/2 * angle * r^2), or even n-spheres ((n-1)/n * tau * r^n).

In both instances, the circle formula is a special case: 1/2 * tau * r^2 = pi * r^2.  The use of pi is an aesthetic optimization, not representative of any underlying geometric relationship.  (However, the use of pi in runtime optimization is still applicable for these special cases.)

This mere coincidence becomes even more obvious when looking at the derivation of the above formulae, and as with everything discussed heretofore, is already discussed in the Tau Manifesto.  Incidentally, I recommend anyone still wavering to read it for the benefit of making more informed opinions.
----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-38532

Author: sbaird (Simon Baird)
Status: Assigned
Priority: Low
Assignee: matz (Yukihiro Matsumoto)
Category: core
Target version: Next Major


Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.


-- 
http://bugs.ruby-lang.org/

[ruby-core:63389] [ruby-trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[simon.baird]

Issue #4897 has been updated by Simon Baird.


Since today is 6/28, here's a pull request on trunk:

* https://github.com/ruby/ruby/pull/644

See also:

* http://tauday.com/state-of-the-tau

Best wishes and Happy Tau Day... :)

----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-47432

* Author: Simon Baird
* Status: Assigned
* Priority: Low
* Assignee: Yukihiro Matsumoto
* Category: core
* Target version: Next Major
----------------------------------------
Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.

---Files--------------------------------
tau.patch (1.2 KB)
tau.patch (1.2 KB)


-- 
https://bugs.ruby-lang.org/

[ruby-core:69839] [Ruby trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[simon.baird]

Issue #4897 has been updated by Simon Baird.


I'm a bit late, but here it is rebased for Tau Day 2015:

* https://github.com/ruby/ruby/pull/644



----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-53239

* Author: Simon Baird
* Status: Assigned
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.

---Files--------------------------------
tau.patch (1.2 KB)
tau.patch (1.2 KB)


-- 
https://bugs.ruby-lang.org/

[ruby-core:70054] [Ruby trunk - Feature #4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[muraken]

Issue #4897 has been updated by Kenta Murata.


As I wrote in https://bugs.ruby-lang.org/issues/4897, I closed the pull-request for the present time.


----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-53477

* Author: Simon Baird
* Status: Assigned
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.

---Files--------------------------------
tau.patch (1.2 KB)
tau.patch (1.2 KB)


-- 
https://bugs.ruby-lang.org/

[ruby-core:76831] [Ruby trunk Feature#4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[simon.baird]

Issue #4897 has been updated by Simon Baird.


This may be of interest: Guido van Rossum recently reopened the Python version of this request and is going to add tau to Python. See https://bugs.python.org/issue12345 .

----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-60057

* Author: Simon Baird
* Status: Assigned
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.

---Files--------------------------------
tau.patch (1.2 KB)
tau.patch (1.2 KB)


-- 
https://bugs.ruby-lang.org/

[ruby-core:77620] [Ruby trunk Feature#4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[nobu]

Issue #4897 has been updated by Nobuyoshi Nakada.


At the developers' meeting this week, mrkn suggested `TWO_PI` instead.

----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-60888

* Author: Simon Baird
* Status: Assigned
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.

---Files--------------------------------
tau.patch (1.2 KB)
tau.patch (1.2 KB)


-- 
https://bugs.ruby-lang.org/

[ruby-core:77621] Re: [Ruby trunk Feature#4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[RRRoy BBBean]

Why would someone want to use Ruby for scientific computing, when Python 
offers an awesome collection of scientific packages with first-class 
support?

Isn't Ruby supposed to be a great language for web development, and 
that's about the extent of it?

[I'm playing the Devil's Advocate here.]

Specifically, wouldn't an interconnected system of Science/Math packages 
be a more appropriate place for Mathematical and Scientific constants? 
That way, they could be organized to facilitate ease-of-use while 
eliminating redundancy. They might even be curated to avoid the prospect 
of wholesale duplicating CRC manuals in Ruby code.

Would such an interconnected system be packaged as a bunch of individual 
gems, or is there some higher-level packaging concept than the Ruby gem?

I personally think gems are best when kept as small as possible, highly 
cohesive and highly coherent. But that creates a secondary problem? How 
to organize larger units of reusable code? I don't know.


On 10/13/2016 10:12 PM, nobu@ruby-lang.org wrote:
> Issue #4897 has been updated by Nobuyoshi Nakada.
>
>
> At the developers' meeting this week, mrkn suggested `TWO_PI` instead.
>
> ----------------------------------------
> Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
> https://bugs.ruby-lang.org/issues/4897#change-60888
>
> * Author: Simon Baird
> * Status: Assigned
> * Priority: Normal
> * Assignee: Yukihiro Matsumoto
> ----------------------------------------
> Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.
>
> Here is a patch on trunk that implements this:
> http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html
>
> Allow me to anticipate and respond in advance to some common objections:
>
> 1. It's easy to define it yourself so why put this in core.
> Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.
>
> 2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
> The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.
>
> ---Files--------------------------------
> tau.patch (1.2 KB)
> tau.patch (1.2 KB)
>
>

[ruby-core:77622] gems and higher level concepts (was [Ruby trunk Feature#4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi.)

[Martin J. Dürst]

On 2016/10/14 13:35, RRRoy BBBean wrote:

> Would such an interconnected system be packaged as a bunch of individual
> gems, or is there some higher-level packaging concept than the Ruby gem?
>
> I personally think gems are best when kept as small as possible, highly
> cohesive and highly coherent. But that creates a secondary problem? How
> to organize larger units of reusable code? I don't know.

It's easy. Gems can depend on other gems. So we can have some highly 
cohesive and highly coherent gems at the bottom, and then other, more 
application-oriented gems that pull the necessary basic gems together. 
This can be done on more and more levels if necessary.

Composition is a great concept, and applying it recursively is even better.

Regards,   Martin.

[ruby-core:77624] [Ruby trunk Feature#4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[simon.baird]

Issue #4897 has been updated by Simon Baird.


Nobuyoshi Nakada wrote:
> At the developers' meeting this week, mrkn suggested `TWO_PI` instead.

I don't think TWO_PI would be very useful since it misses the main point of tau, which is that tau is the correct circle constant, (and pi is a 2000 year old blunder)[1]. If you consider this diagram [2] with TWO_PI in place of tau, then it loses its meaning.

Defining HALF_TAU could be useful though. ;)

[1] Of course not everyone agrees on this, but http://tauday.com/tau-manifesto is quite convincing IMO

[2] http://tauday.com/assets/figures/tau-angles.png

----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-60890

* Author: Simon Baird
* Status: Assigned
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.

---Files--------------------------------
tau.patch (1.2 KB)
tau.patch (1.2 KB)


-- 
https://bugs.ruby-lang.org/

[ruby-core:77625] [Ruby trunk Feature#4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[shyouhei]

Issue #4897 has been updated by Shyouhei Urabe.


Just to add my POV:

I'm a complete amateur in pure Mathematics.  To me who is an outsider of academia,  I can't say we should accept or reject this request right now.  All I can say is it seems not widely used in papers for some reason I don't know.  It's not clear to me wether the constant τ is just yet to receive wider acceptance because it's relatively young, or is actively receiving low marks from academic community.  I'm just not sure.

This constant is a constant (by nature), so once introduced in ruby it's highly expected to stay defined forever.  Because of this property I'm afraid of wrong decision.  Is it really safe we add this?  In order to make this sure I think we need either more time, or an expert's counsel, or maybe both.

----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-60891

* Author: Simon Baird
* Status: Assigned
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.

---Files--------------------------------
tau.patch (1.2 KB)
tau.patch (1.2 KB)


-- 
https://bugs.ruby-lang.org/

[ruby-core:77629] [Ruby trunk Feature#4897] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[simon.baird]

Issue #4897 has been updated by Simon Baird.


See also https://github.com/jneen/math-tau .

----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-60899

* Author: Simon Baird
* Status: Assigned
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.

---Files--------------------------------
tau.patch (1.2 KB)
tau.patch (1.2 KB)


-- 
https://bugs.ruby-lang.org/

[ruby-core:78304] [Ruby trunk Feature#4897][Rejected] Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/

[matz]

Issue #4897 has been updated by Yukihiro Matsumoto.

Status changed from Assigned to Rejected

For the time being, use `math-tau` gem.
I will add it after (and only after) it became time-proven major, probably due to Python's tau.

Matz.


----------------------------------------
Feature #4897: Define Math::TAU and BigMath.TAU. The "true" circle constant, Tau=2*Pi. See http://tauday.com/
https://bugs.ruby-lang.org/issues/4897#change-61666

* Author: Simon Baird
* Status: Rejected
* Priority: Normal
* Assignee: Yukihiro Matsumoto
----------------------------------------
Firstly please read the Tau Manifesto at http://tauday.com/ . It's quite long but essential to understanding why this is a good idea.

Here is a patch on trunk that implements this:
http://simonbaird.blogspot.com/2011/06/tau-in-ruby.html

Allow me to anticipate and respond in advance to some common objections:

1. It's easy to define it yourself so why put this in core.
Possibly correct, but I think this is the right thing to do. Tau is important. And it's a pretty small patch.

2. If this constant goes in then pretty soon someone will want every other math constant and there are hundreds of them. (Slippery slope argument).
The circle constant is one of the two most important numbers is mathematics. It's not just another math constant. We already define Pi.

---Files--------------------------------
tau.patch (1.2 KB)
tau.patch (1.2 KB)


-- 
https://bugs.ruby-lang.org/