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Groups > comp.lang.forth > #49275
| From | "WJ" <w_a_x_man@yahoo.com> |
|---|---|
| Newsgroups | comp.sys.raspberry-pi, comp.lang.forth |
| Subject | Re: Jazelle? |
| Date | 2016-07-21 10:43 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <nmq8vk$b52$1@dont-email.me> (permalink) |
| References | (3 earlier) <MPG.31f93e8b429c8383989804@172.16.0.1> <nmnge0$rri$1@dont-email.me> <2016Jul20.121415@mips.complang.tuwien.ac.at> <nmnvi0$e7s$1@dont-email.me> <2016Jul20.163523@mips.complang.tuwien.ac.at> |
Cross-posted to 2 groups.
Anton Ertl wrote:
> : compute-q { f: a f: b/2 f: c -- q }
> b/2 b/2 f* a c f* f- fsqrt
> b/2 f0< if fnegate then \ avoids cancelation by the F+ below
> b/2 f+ ;
>
> : quadratic { f: a f: b f: c -- x1 x2 }
> a b f2/ c compute-q { f: q }
> q a f/ c q f/ ;
Charles Moore said that local variables are harmful,
but Anton had to use them. Imagine how unwritable
and how unreadable his code would have been without them!
It's atrocious enough already.
Testing:
3e0 -10e0 5e0 quadratic ok
.s <0> ok
f. -0.612574113277207 ok
f. -2.72075922005613 ok
Both results are wrong.
Note a very important fact. None of the Forth "gurus"
posting in this thread noticed that his code produces
absolutely incorrect results. Correctness matters
far less than dogmatic devotion to a stone-age language.
Julia:
quad(a,b,c) = (t = -b/2a; q = sqrt(b^2 - 4a*c)/2a; [t+q, t-q])
julia> quad(3,-10,5)
2-element Array{Float64,1}:
2.72076
0.612574
julia> quad(1,2,-8)
2-element Array{Float64,1}:
2.0
-4.0
Employing the other formula, but using a real language (Julia):
calc_q(a, b_2, c) = copysign(sqrt(b_2^2 - a*c), b_2) + b_2
quad(a,b,c) = (q = -calc_q(a, b/2, c); [q/a, c/q])
julia> quad(1,2,-8)
2-element Array{Float64,1}:
-4.0
2.0
julia> quad(3,-10,5)
2-element Array{Float64,1}:
2.72076
0.612574
--
Amazon bans book. After nearly a month on the site, all traces of the book and
its 80 reviews have been removed.
http://jamesfetzer.blogspot.com/2015/11/debunking-sandy-hook-debunkers-5.html
https://www.youtube.com/watch?v=EEl_1HWFRfo
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Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-20 10:31 +0100
Re: Jazelle? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-07-20 10:14 +0000
Re: Jazelle? Chris Curl <ccurl609@gmail.com> - 2016-07-20 05:37 -0700
Re: Jazelle? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-07-20 13:36 +0000
Re: Jazelle? "WJ" <w_a_x_man@yahoo.com> - 2016-07-20 13:06 +0000
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-20 14:49 +0100
Re: Jazelle? hughaguilar96@gmail.com - 2016-07-20 08:48 -0700
Re: Jazelle? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-07-20 14:35 +0000
Re: Jazelle? mm0fmf <none@invalid.com> - 2016-07-20 17:39 +0100
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-20 20:30 +0100
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 15:35 -0400
Re: Jazelle? mhx@iae.nl - 2016-07-20 13:27 -0700
Re: Jazelle? "WJ" <w_a_x_man@yahoo.com> - 2016-07-21 09:41 +0000
Re: Jazelle? hughaguilar96@gmail.com - 2016-07-21 17:24 -0700
Re: Jazelle? "WJ" <w_a_x_man@yahoo.com> - 2016-07-21 10:43 +0000
Re: Jazelle? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-07-21 12:44 +0000
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-21 22:59 +0100
Re: Jazelle? anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2016-07-22 06:42 +0000
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-22 12:03 +0100
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-22 09:05 -0400
Re: Jazelle? Cecil Bayona <cbayona@cbayona.com> - 2016-07-22 10:09 -0500
Re: Jazelle? Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2016-07-22 19:20 +0300
Re: Jazelle? Brad Eckert <hwfwguy@gmail.com> - 2016-07-22 09:35 -0700
Re: Jazelle? "WJ" <w_a_x_man@yahoo.com> - 2016-07-25 10:43 +0000
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-26 11:41 +0100
Re: Jazelle? Julian Fondren <julian.fondren@gmail.com> - 2016-07-26 04:26 -0700
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-26 11:20 -0400
Re: Jazelle? Doug Hoffman <glidedog@gmail.com> - 2016-07-20 06:44 -0400
Re: Jazelle? "gareth G4SDW GQRP #3339" <no.spam@thank.you.invalid> - 2016-07-20 14:52 +0100
Re: Jazelle? "WJ" <w_a_x_man@yahoo.com> - 2016-07-20 14:33 +0000
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 10:52 -0400
Re: Jazelle? alister <alister.ware@ntlworld.com> - 2016-07-20 15:40 +0000
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 11:46 -0400
Re: Jazelle? hughaguilar96@gmail.com - 2016-07-20 09:25 -0700
Re: Jazelle? hughaguilar96@gmail.com - 2016-07-20 09:22 -0700
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 13:14 -0400
Re: Jazelle? hughaguilar96@gmail.com - 2016-07-20 21:44 -0700
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-21 01:32 -0400
Re: Jazelle? Cecil Bayona <cbayona@cbayona.com> - 2016-07-21 02:21 -0500
Re: Jazelle? Brad Eckert <hwfwguy@gmail.com> - 2016-07-21 17:13 -0700
Re: Jazelle? hughaguilar96@gmail.com - 2016-07-21 17:42 -0700
Re: Jazelle? humptydumpty <ouatubi@gmail.com> - 2016-07-23 10:08 -0700
Re: Jazelle? hughaguilar96@gmail.com - 2016-07-23 13:55 -0700
Re: Jazelle? humptydumpty <ouatubi@gmail.com> - 2016-07-24 02:22 -0700
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 10:56 -0400
Re: Jazelle? Brad Eckert <hwfwguy@gmail.com> - 2016-07-20 10:54 -0700
Re: Jazelle? Cecil Bayona <cbayona@cbayona.com> - 2016-07-20 13:33 -0500
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 16:51 -0400
Re: Jazelle? Cecil Bayona <cbayona@cbayona.com> - 2016-07-20 17:09 -0500
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 18:12 -0400
Re: Jazelle? Cecil Bayona <cbayona@cbayona.com> - 2016-07-20 18:41 -0500
Re: Jazelle? rickman <gnuarm@gmail.com> - 2016-07-20 21:01 -0400
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