Ok, let's go with the specifics you mentioned here, first. (I couldn't find the part of the book which matches your expression.)
The >. verb in X >. Y is *not* greater or equal. X >: Y is greater or equal. X >. Y is maximum value -- the result is whichever values from X and Y are the largest (matched based on position, of course). 1 2 3 4 >. 5 4 3 2 5 4 3 4 So, what's happening there would be d=: 0 1 2 3 4 d</d 0 1 1 1 1 0 0 1 1 1 0 0 0 1 1 0 0 0 0 1 And, d >. d</d is going to pick the largest value from d or d</d. For the first row, it's looking for whichever value is larger than 0 (the first element of d) in d</d. So that row gets 0 1 1 1 1. After that, since each value from d is at least as large as any value of d</d, it's going to have rows which are all corresponding values from d. So, you get: d >. d</d 0 1 1 1 1 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 Anyways... looking for the text in https://www.jsoftware.com/books/pdf/arithmetic.pdf which seems to correspond to this, I think the verbs you are referring to are 'over' and 'by' referenced on page 15. This looks like a consequence of a flawed edit. They were probably defined in an earlier version of the book. You can still find definitions of them at https://www.jsoftware.com/help/dictionary/intro03.htm (for now, at least). But, of course, they're not using <. in that 'J1' example on page 15, so maybe I'm guessing wrong about what you are encountering. (Er... that's book page 15 -- it's pdf page 20.) Please let me know if you were somewhere else in that book? Thanks, -- Raul On Sun, Sep 5, 2021 at 5:21 PM joseph turco <italian.pepe...@gmail.com> wrote: > > Hey Raul, > > I was speaking in context to the book 'arithmetic' not in general. In the > exercises for the first chapter for example, it says to use two user > defined verbs that the book has you define earlier in the chapter, but the > problem is, is that you never do that ( i used the search function, not > just scrolling up and down, there is no sign of these verbs). Another > problem was that the following was a exercise and was asked by the book to > write these out before computing it. i liked that idea. but the following > never explained: > > d =: 0 1 2 3 4 > > d >. d</d > > 0 1 1 1 1 > > 1 1 1 1 1 > > 2 2 2 2 2 > > 3 3 3 3 3 > > 4 4 4 4 4 > > d <. d</d > > 0 0 0 0 0 > > 0 0 1 1 1 > > 0 0 0 1 1 > > 0 0 0 0 1 > > 0 0 0 0 0 > > > if >. is greater or equal to, why is 2's being printed across the chart? > > why with <., are true and false values being printed than the nouns in the > vector like the >. shows? > > maybe the book really isn't for the level of novice i am, or the book just > isn't laid out correctly. As i said > > i am reading the J primer and that has been much better so far. If i > misread something in the 'arithmetic' book > > id like to be proven wrong. In regards to study time, ive been using most > of my spare time learning to program as i > > find it fascinating, and it also doesn't cost me a dime (well, other than > the hydro). > > > regards, > > > Joseph Turco > > > The book > > On Sun, Sep 5, 2021 at 4:36 PM Raul Miller <rauldmil...@gmail.com> wrote: > > > You might also want to try some of the J labs. > > > > Also... my experience was that I needed to circle back and re-read > > things after learning parts of the language. While I suppose it's > > technically true that "all you need to know is how to count", that's > > true in the sense that calculus is just another method for counting. > > You still need to be able to work through the examples and understand > > what you are seeing... > > > > But be sure to pace yourself. A half hour a day is better than 4 hours > > once a week. > > > > Thanks, > > > > -- > > Raul > > > > On Sun, Sep 5, 2021 at 1:41 PM joseph turco <italian.pepe...@gmail.com> > > wrote: > > > > > > Hello R.E.Boss > > > > > > I Do not have any post-secondary education, and am solely programming > > just > > > out of recreation is the best way i can put it. Ive only dabbled in other > > > programming languages and didn't find them interesting. I actually Found > > J > > > after having issues getting Dyalog APL running on my 64-bit ARM computer, > > > and J worked perfectly. I also appreciate the fact it uses ASCII > > characters > > > and not a special character set. I am an italian-canadian, and only know > > > the language from being raised around it, so its what i know other than > > > english, that's not saying i hate it. I actually dumped the arithmetic > > book > > > as it doesn't make much sense of explaining things (the book says all you > > > need to know is how to count) and its missing things that are referred in > > > some sections. Im giving the J Primer a crack too see if helps me. > > > > > > regards, > > > > > > Joseph Turco > > > > > > On Sun, Sep 5, 2021 at 11:51 AM R.E. Boss <r.e.b...@outlook.com> wrote: > > > > > > > Can you tell us a bit about your background? Did you program before? > > Which > > > > languages? Why was Italian not a language to learn for fun? > > > > > > > > Welcome anyhow! > > > > One can have worse reasons to learn a language. > > > > > > > > > > > > R. E. Boss > > > > > > > > > > > > -----Original Message----- > > > > From: Programming <programming-boun...@forums.jsoftware.com> On > > Behalf Of > > > > joseph turco > > > > Sent: zaterdag 4 september 2021 17:01 > > > > To: programm...@jsoftware.com > > > > Subject: Re: [Jprogramming] Hello, new programmer here! > > > > > > > > Thanks Bo, > > > > > > > > I am actually following the 'Learning J' book that is on the J website. > > > > its been good so far, but i've been getting a bit confused with the '&' > > > > verb and '@:' verb and what makes them different (they are verbs > > right?). > > > > Its funny because i was bored of math class in high school and was one > > of > > > > those kids who "skipped" a lot, but using a language like J has made me > > > > fascinated with what is possible. > > > > > > > > regards, > > > > > > > > Joseph Turco > > > > > > > > On Sat, Sep 4, 2021 at 7:06 AM 'Bo Jacoby' via Programming < > > > > programm...@jsoftware.com> wrote: > > > > > > > > > Welcome Joseph! > > > > > Being an old programmer I became fascinated by J. > > > > > There is a lot to learn, but some of it is unnecessary to the > > beginner. > > > > > The 3 operations, addition (+), multiplication (*), and > > exponentiation > > > > > (^), are sufficient for many computations. Having sign change (-) you > > > > > do not need subtraction (b-a)=(b+-a), and division > > > > > (b%a)=(*/(b,a)^1,-1), nor (%a)=(a^-1), (%:a)=(a^2^-1), (+:a)=(a*2), > > > > > (-:a)=(a*2^-1), (-.a)=(1+-a), (>:a)=(1+a), (*:a)=(a^2). > > > > > Note that expressions are evaluated from right to left: > > > > > (a^b^c)=(a^(b^c)) Have fun! > > > > > Bo. > > > > > Den fredag den 3. september 2021 20.24.11 CEST skrev joseph turco > > > > > < > > > > > italian.pepe...@gmail.com>: > > > > > > > > > > Hello all, > > > > > > > > > > I am a novice programmer and was looking for a language to learn for > > > > > fun. I tried APL but I couldn't get the keybindings to work on my > > > > > computer. I then found J from reddit and some google fu. It looks > > like > > > > > an awesome language, and i can't wait to learn more and make some fun > > > > > programs. I'd thought i'd pop in and say hello, so hi! > > > > > > > > > > regards, > > > > > > > > > > Joseph TUrco > > > > > > > ---------------------------------------------------------------------- > > > > > For information about J forums see > > http://www.jsoftware.com/forums.htm > > > > > > > > > > > > ---------------------------------------------------------------------- > > > > > For information about J forums see > > http://www.jsoftware.com/forums.htm > > > > > > > > > ---------------------------------------------------------------------- > > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > ---------------------------------------------------------------------- > > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
