Re: [Jprogramming] Extended precision question
Mike, Many thanks for the guidance. I’d already determined that my x: approaches to #66 were going to involve waiting for the earth to crash into the sun—or, equally unattractive, paying Google Cloud Platform for a fleet of “Godzilla” class VMs—so I am looking in other directions. I took a
Re: [Jprogramming] Extended precision question
Mainly for Ed Gottsman: Chat really, but the thread is already here. I've just solved Euler Problem 788 with the assistance of extended precision numbers. The solution is slow, taking over 14 minutes, but at least it's less than the lifetime of the universe, unlike my (projected)
Re: [Jprogramming] Extended precision question
If you don't mind some limitations, that: (*) the ... token can only be used in explicit definitions (*) the ... token must be preceded by a space (*) the resulting definitions do not actually contain the ... delimited coments (*) these definitions must use a lone ')' as the closing
Re: [Jprogramming] Extended precision question
Hey, Ed, Regarding comments, J has the NB. and a built-in Note noun. If you type in Note, hit enter, you'd get its definition (on 903 and 904) 3 : '0 0 $ 0 : 0' :[ And, whilst experimenting a bit to get the syntax highlighting for the kakoune text editor right, I can say with confidence
Re: [Jprogramming] Extended precision question
Ed, no apology required :) For the first approach: If you want that, you can just start using it. LEO came to my mind but you could as well support it in another editor. Write a function stripping your code off those comments and feeding the remaining code to J. Not much of a hassle except for
Re: [Jprogramming] Extended precision question
Hauke, My apologies: I expressed myself awkwardly. No disrespect was meant to any editor. :-). Emacs and vim would be my choices, too, were I feeling a lot more ambitious. I have the sense that there are two basic approaches under discussion. In the first (the one I think you’re
Re: [Jprogramming] Extended precision question
Smarter than emacs? Vim. :) editor wars aside, I’m having a hard time imagining any editor smarter than these two They may call themselves “smarter” but mostly that translates to “more cumbersome”. folds are natural in any coding editor, and I guess Tim Pope would come up with a solution
Re: [Jprogramming] Extended precision question
I expect that your ... could be made to work in explicit definitions, but it would be a bit of work (getting error reporting right might be a bit of a headache, and the interactive debugger would probably have to be partially rebuilt to work with this concept). Plus, of course, the actual
Re: [Jprogramming] Extended precision question
Jan-Pieter, I like that file format a lot. Like JSON, it’s human- and machine-readable. Further, a “slightly smart” editor (here I’m thinking perhaps of emacs macros) could toggle between it (one token per line with comments) and a conventional view (all tokens on one line, no comments). A
Re: [Jprogramming] Extended precision question
I actually was intending for quite a while to propose an extension to comments along the lines of the suggestions in this thread: to use ... as line continuation indicator that turns everything after it up to and including the next line break to be considered comment, and still considers the line
Re: [Jprogramming] Extended precision question
The LEO editor might be a good fit. And yes, it’s really freaking (cool). A script could generate the actual .ijs from snippets that are well documented and those snippets may well be single J tokens. Am 28.04.22 um 08:10 schrieb Ed Gottsman: LOL. Fair question. Here’s another: if J adopted a
Re: [Jprogramming] Extended precision question
Raul, D’oh. *Sigh*. It helps. Many thanks. I appreciate your patience as much as your knowledge and willingness to help. Ed Sent from my iPad > On Apr 27, 2022, at 3:36 PM, Raul Miller wrote: > > You should have used > squares =: *: x: >: ? 1e5 $ 1e11 > > Computing the square using
Re: [Jprogramming] Extended precision question
LOL. Fair question. Here’s another: if J adopted a style standard around ideograms (which are rendered vertically by default) for comments, would that on the one hand slightly increase (as a percentage) its reputation for obscurity among Western programmers but on the other dramatically
Re: [Jprogramming] Extended precision question
Probably more like vert=: {{0!:0;:inv@;;.1 a:,<@}:@;:@,&' NB.';._2 m}} {{)n NB. y Possible squares of integers. Return either integer NB. square roots or 0s. intsqrt=: {{ y * NB. Multiply to produce either integer square roots or 0s y = NB. 1s where the calculated square
Re: [Jprogramming] Extended precision question
I thought what was wanted was to write the _comments_ vertically, as in: mean=: +/ % # NB. i sr d l NB. s ue i e NB.md v n NB. u i g NB. c d t NB. t e h NB. i d NB. o NB. n b NB. y On Wed, 27 Apr 2022, Raul Miller wrote: For what it's worth, J could
Re: [Jprogramming] Extended precision question
For what it's worth, J could easily be written vertically. But that's probably not quite what people would want. vertical=: {{ 0!:0;:inv{.@;:;._2 m}} {{)n mean =: + / % # }}vertical mean 1 2 3 2 -- Raul On Wed, Apr 27, 2022 at 2:01 PM Hauke Rehr wrote: > >
Re: [Jprogramming] Extended precision question
What keeps you from writing your comments vertically‽ Am 27.04.22 um 14:50 schrieb Ed Gottsman: If J were written vertically, it might be easier to comment. -- -- mail written using NEO neo-layout.org --
Re: [Jprogramming] Extended precision question
You should have used squares =: *: x: >: ? 1e5 $ 1e11 Computing the square using floating point and then converting to extended precision means that many of your values in 'squares' are not actually square. For example: x: *: 68824904566 4736867488519007764480 *: x: 68824904566
Re: [Jprogramming] Extended precision question
Oops. Foolish error as I prepared for presentation. My apologies. Here’s the accurate implementation of intsqrt. intsqrt =: 3 : 0 NB. y An array of possible integer squares NB. Return 0 for non-squares or integer roots s * y = x: *: s =. <. 0.5 + x: 10 ^ -: x: 10 ^. y ) Note that it is
Re: [Jprogramming] Extended precision question
Project Euler #66, extended precision integer square roots, no spoilers Continuing the discussion, for which again thank you all: I found that what I really wanted was large *integer* square roots. Since this seems to come up frequently in Project Euler problems and since I believe there are
Re: [Jprogramming] Extended precision question
Hi Ed, I was thinking of explaining Roger's sqrt code as part of next month's NYCJUG. You should take a look: https://www.meetup.com/J-Dynamic-Functional-Programming/ . Cheers, Devon On Fri, Apr 22, 2022 at 12:49 AM Ed Gottsman wrote: > Thanks to everyone who responded and in particular for the
Re: [Jprogramming] Extended precision question
Thanks to everyone who responded and in particular for the link to Roger Hui’s essay. The wiki discussion was also very good. (In an earlier life I disparaged “cargo cult” programming, in which you take a few lines of source you don’t understand and integrate them into your program. [That
Re: [Jprogramming] Extended precision question
One way to obtain high precision roots is to use, say, Newton’s solution to y = x^2 - a : Given an estimate x(n-1), the next estimate is xn = x(n-1) - y/(dy/dx), in Maths notation. In J, (J701 on this iPad), rt =: -:@] + (% +:) NB. x is number whose root is required, y an initial guess
Re: [Jprogramming] Extended precision question
Showing the result in decimal: 23j13": sqrt 1x + *: 9x 9.05000 On Thu, Apr 21, 2022 at 3:18 PM Gilles Kirouac wrote: > Ed If you expand the Extended Integers section (below by bob), you will > see a link to an essay by Roger on 'Extended Precision Functions'. There
Re: [Jprogramming] Extended precision question
Ed If you expand the Extended Integers section (below by bob), you will see a link to an essay by Roger on 'Extended Precision Functions'. There is a Square Root verb. NB. long rational result may exceed line length sqrt 1x + *: 9x
Re: [Jprogramming] Extended precision question
Gilles, In Nuvoc the extended constant notation can be found here https://code.jsoftware.com/wiki/Vocabulary/Constants#Extended_Integers Having said that, it is hidden pretty well and most of its references are previous documentation on the jsoftware site. There is certainly work to be done
Re: [Jprogramming] Extended precision question
Ed You seem unaware of the extended precision constant notation: "digits with a trailing x denote an extended precision integer" https://www.jsoftware.com/help/dictionary/dcons.htm [Where is the equivalent in NuVoc?] I would rather write 1x + *: 9x 82 ~ Gilles
Re: [Jprogramming] Extended precision question
Square root does not produce an extended precision result. <.@%: does produce an extended precision result, but that would not resolve your problem here. FYI, -- Raul On Thu, Apr 21, 2022 at 12:43 PM Ed Gottsman wrote: > > Hello. > > I’m working on the Project Euler “Diophantine equation”
Re: [Jprogramming] Extended precision question
3!:0 %: x: 1 + x: *: x: 9 8 The square root cannot be represented exactly. Henry Rich On 4/21/2022 12:43 PM, Ed Gottsman wrote: Hello. I’m working on the Project Euler “Diophantine equation” problem (#66) and using J’s extended precision facilities. I’ve run into behavior that
[Jprogramming] Extended precision question
Hello. I’m working on the Project Euler “Diophantine equation” problem (#66) and using J’s extended precision facilities. I’ve run into behavior that confuses me. Boiled down (and overusing x: just to be sure): x: %: x: 1 + x: *: x: 9 9 That is (if my syntax is right),
