**⚠️ Warning: This is a draft ⚠️**

This means it might contain formatting issues, incorrect code, conceptual problems, or other severe issues.

If you want to help to improve and eventually enable this page, please fork RosettaGit's repository and open a merge request on GitHub.

I don't like being pushed to use obscure (but more stable) algorhithm over algorithm everyone instantly recognises. Said that, I could live with it. But I want to point that:

- link for "What Every Scientist Should Know About Floating-Point Arithmetic" is dead;
- one can google for it, but formatting is different, so how to find what "page 9" actually is?
- quoted in the text, "Suggested by Middlebrook (D-OA), a better numerical method: to define two parameters q=sqr(ac)/b (...)" naturally fails over if a>0 and c<0. "do it better" ?

I clearly see come of programs (Ada, and some marked as "translation of Ada") use
(b^2-4ac)/2*a,
there correct way is
(b^2-4ac)/(2*a).
I wonder why noone spotted this earlier!

Forsythe, Michael Malcolm and Cleve Mole suggest to try it on a=1, b=-10^{5}, c=1, but Ada sample code uses -10e5, which is indeed -1e6 (-10^{6}), if I was not wrong since I knew the "e" notation... --[[User:ShinTakezou|ShinTakezou]] 21:24, 22 June 2009 (UTC)

Basically all the test cases had a = 1, :-) So I added some test cases especially where a ≠ 1, hence 2*a ≠ 2/a.... [[User:NevilleDNZ|NevilleDNZ]] 14:28, 16 September 2010 (UTC)

In the example above (2nd line) (-10^{6}) isn't the same as -1e6. The former is -1,000,000 and the latter is +1,000,000. --[[User:Gerard Schildberger|Gerard Schildberger]] 18:11, 25 June 2011 (UTC)

Other way round surely: $-10^n$ will always be positive when n is even. --Laurie Alvey 10:45, 19 May 2015 (UTC)

== J example ==
Dumontier, hope you don't mind me replacing your example code. I understood that you were trying to illustrate the generality of `p.`

however your example used a quadratic, that had already been shown above. If you were trying to illustrate some other point I apologise! --[[User:Tikkanz|Tikkanz]] 23:14, 14 October 2009 (UTC)

== C examples ==

I just provided a (more) correct C version, and am now tempted to remove other C examples, because the task specifically mentioned the shortcoming of the naive method, yet they went on that route anyway. Opinions? --[[User:Ledrug|Ledrug]] 09:08, 25 June 2011 (UTC)

~~Wait, what? The existing C and C++ code gives 10^20 and 10^-20 as roots to equation ~~`x^2 - 10^-20 x + 1 == 0`

? What the? --[[User:Ledrug|Ledrug]] 09:22, 25 June 2011 (UTC)

Eh never mind that, and sorry about making a mess on the incorrect tags--I need sleep... --[[User:Ledrug|Ledrug]] 09:40, 25 June 2011 (UTC)

== Clojure example ==

Why are there 4 functions for clojure?

What I mean is that all of that can be simplified into:

(defn quadratic "Compute the roots of a quadratic in the form ax^2 + bx + c = 0 Returns any of nil, a float, or a vector." [a b c] (let [sq-d (Math/sqrt (- (* b b) (* 4 a c))) f #(/ (% b sq-d) (* 2 a))] (cond (neg? sq-d) nil (zero? sq-d) (f +) (pos? sq-d) [(f +) (f -)] :else nil))) ; maybe our number ended up as NaN

I find it ridiculous to have that much verbiage on 1 example.