From: pharrington <xenogenesis@...>
Date: 2009-12-28T15:35:05+09:00
Subject: Re: Trig value errors

On Dec 28, 12:58 am, jzakiya <jzak...@gmail.com> wrote:
> On Dec 28, 12:45 am, Walton Hoops <wal...@vyper.hopto.org> wrote:
>
>
>
>
>
> > On 12/27/2009 10:35 PM, jzakiya wrote:
>
> > > On Dec 27, 11:50 pm, Seebs<usenet-nos...@seebs.net>  wrote:
>
> > >> On 2009-12-28, jzakiya<jzak...@mail.com>  wrote:
>
> > >>> All I can say is....
>
> > >>> Against stupidity the Gods themselves contend in vain. :(
>
> > >> This adequately summarizes the difficulty people have had getting you to
> > >> understand why it is ridiculous to try to "fix" sin(180) but not to try to
> > >> "fix" sin(45).
>
> > >> -s
> > >> --
> > >> Copyright 2009, all wrongs reversed.  Peter Seebach / usenet-nos...@seebs.nethttp://www.seebs.net/log/<-- lawsuits, religion, and funny pictureshttp://en.wikipedia.org/wiki/Fair_Game_(Scientology)<-- get educated!
>
> > > No, YOU still don't seem to know the difference between
> > > precision an accuracy.
>
> > > If you can READ I said my method is no more precise, i.e
> > > it CANNOT resolve angular differences past the inherent
> > > precision of the native trig functions.
>
> > > But what you, and your cohorts, don't want to deal with, is my method
> > > IS MORE ACCURATE for sin|cos on the x|y axis angles, whereas the
> > > native functions are INACCURATE.
>
> > > So, I DON'T CARE how precise any of the other angles
> > > are, because they all are ACCURATE to the precision that
> > > the native functions have. I said this many times, and
> > > others have tried to explain the difference too.
>
> > > One thing is VERY CLEAR though.
>
> > > YOU, can't SHOW that my method is inaccurate for any
> > > angle value. Can YOU?
>
> > Actually, he did... lets review:
>
> > On 12/27/2009 8:56 PM, John W Higgins wrote:
>
> > > First, to show that the standard methods show no greater precision lets test
> > > 87 degrees shall we.
>
> > > 1.0 - (sin(PI/180*87) ** 2 + cos(PI/180*87) ** 2)
> > > =>  1.11022302462516e-16
>
> > > So we fail with the standard and yours works
>
> > > 1.0 - (sin1(PI/2/90*87) ** 2 + cos1(PI/2/90*87) ** 2)
> > > =>  0.0
>
> > > But wait shall we - lets look at 67 degrees ok?
>
> > > 1.0 - (sin(PI/180*67) ** 2 + cos(PI/180*67) ** 2)
> > > =>  0.0
>
> > > 1.0 - (sin1(PI/180*67) ** 2 + cos1(PI/180*67) ** 2)
> > > =>  2.22044604925031e-16
>
> > > Oh no - we have a problem - your calculation fails when the standard works.
>
> > Thus, your method is inaccurate for the angle value of 67.
>
> > > Ah... A Brain is such a terrible thing to waste. :(
>
> My methods
>
> >sin1(67*degrees) => 0.92050485345244
> >cos1(67*degrees) => 0.39073112848927
>
> Ruby methods
>
> >sin(67*degrees) => 0.92050485345244
> >cos(67*degrees) => 0.39073112848927
>
> Same answers.
>
> It's clear you jokers just like to argue and spew nonsense. You make
> stupid statements and provide no
> data to establish your claims. But I guess well thought
> out and consistent reproducible claims are just too
> much for you guys to produce.
>
Not sure at this point if you're just a brilliant troll, or actually
believe what you're posting, but I can't sleep right now so :\

But eh,

ruby-1.9.1-p376 > degrees = PI/180
 => 0.0174532925199433
ruby-1.9.1-p376 > sin(67*degrees)
 => 0.92050485345244
ruby-1.9.1-p376 > sin1(67*degrees)
 => 0.92050485345244
ruby-1.9.1-p376 > cos(67*degrees)
 => 0.390731128489274
ruby-1.9.1-p376 > cos1(67*degrees)
 => 0.390731128489274
ruby-1.9.1-p376 > cos(67*degrees) == cos1(67*degrees)
 => false
ruby-1.9.1-p376 > sin(67*degrees) == sin1(67*degrees)
 => false


Are you saying that Ruby is lying about Math.sin and your sin1
functions returning different values? Also, as has been pointed out
previously, what's displayed when a float is converted to a string is
not necessarily indicative of its actual, internal value.

Also, as has been pointed out, Math::PI is *not* the ratio of a
circle's circumference to its diameter, so even disregarding inherent
floating point imprecision, ranting about the miniscule inaccuracy of
trigonomic functions using this value is pointless because *we're not
even using 100% accurate data to begin with*.




> Are you guys Republicans and/or Global Climate Change deniers too?
If you're not a troll, you should really calm down, lay off the
mailing lists for awhile, and learn how to rationally think things
through and except advice/criticism