The APL Orchard

RGS

6:23 AM

@JeffZeitlin awesome, this worked like a charm :)

Bubbler

CMP: Should we have a tips question common to APL family languages?

Adám

@Bubbler for the outer product on booleans? and 1/-1 base

@Bubbler Problem is to show example code. You'd have to show multiple variants. An d which languages to include? APL and J, but also K? Jelly?

Bubbler

@Adám Yeah, that's a problem. I do know multiple ideas are applicable to both APL and J, but I have no idea how it'll extend to K.

(I won't count Jelly since its primitive set is quite different from its ancestors.)

Bubbler

6:45 AM

Maybe I'd just crosspost on APL and J tips.

Bubbler

8:37 AM

@Adám On this wiki page, "The Dyalog APL primitive Nest (⊆), which encloses a non-simple argument..." sounds wrong to me

Especially given that the nickname of ⊆ is "enclose-if-simple"

Adám

@Bubbler Fixed.

Bubbler

So fast!

Also, is there a reason why many primitives still don't have their respective pages?

Adám

@Bubbler Two reasons actually: 1) Nobody took the effort to create them, 2) It isn't documentation, we don't really need pages for "uninteresting" primitives.

Bubbler

8:58 AM

@Adám Objections to the latter: 1) Every primitive is interesting in some way (i.e. it has its own uses), otherwise it wouldn't have been a primitive anyway; 2) Wiki pages are linked to each other, and absent pages are shown in red which doesn't give a nice impression.

Adám

@Bubbler That's why I put "" on "uninteresting". By all means, start writing!

Bubbler

I was just about to ask if I may start filling them in. I'll take it as an affirmative :)

RGS

9:47 AM

@JamesHeslip I thought there was going to be some follow-up on this :p

James Heslip

@RGS apologies, there probably was- I got tired :D

RGS

@JamesHeslip No problem xD being a product of this generation probably also made me too impatient :/

James Heslip

@RGS No, don't worry. I think I was just going to say that I admire your passion for the language, and desire to learn :)

Do you work in APL, or just a hobbyist?

RGS

@JamesHeslip ah thanks; I am a learner, that's what I do best. And APL really is fun for me, it makes a lot of sense

@JamesHeslip just a hobbyist :)

Bubbler

@Adám As a starting point, I filled in the built-ins template. Looks good?

^ (mainly regarding the names used and classifications)

Adám

10:14 AM

@Bubbler Nice job. 1) I don't think you need to expand the groups for comparison, Boolean, and set functions. 2) I'd put Membership and Find with in computational, like Match and Nub Sieve.

@Bubbler What about quad names? You probably don't want to flood the template with all of those…

Bubbler

@Adám I guess I'll stick to the ones already mentioned somewhere in the wiki (that is, if I actually get to work on it).

IO and ML are already there, I've seen references to CT and RL, and probably DIV and PP are worth mentioning too. (Also the I/O ones if we count them.)

Adám

@Bubbler The Quad names article mentions a bunch.

Bubbler

@Adám Most of them don't have links attached (and are not very likely to be referenced in other pages), so I see them as low-priority.

Jeff Zeitlin

@Adám - Is it Dyalog's intent that n versions of Dyalog APL can coexist on one computer?

Adám

@JeffZeitlin Yes, but they have to differ in at least one of major version number, minor version number, bit-width, or character type. It is not enough for them to differ in build number.

Jeff Zeitlin

10:30 AM

@Adám - OK. I was wondering, because it seemed to me that having a separate user files folder for each version (and including the version in the folder name) might have been "overkill".

Adám

@JeffZeitlin Right, but you can put things in the generic "Dyalog APL Files" folder and it'll get picked up by all versions.

Jeff Zeitlin

@Adám - (I don't think I have one of those...)

dzaima

12:02 PM

@Adám i'd leave comparisons grouped (the joined page is probably more useful than the separate ones imo), and boolean functions should definitely be unwrapped because lcm/gcd

RGS

@Adám Following up on this ^ it might make sense to link the notebook on the 6 comparison functions from the wiki page on the comparison functions

Adám

12:30 PM

@RGS Absolutely. Do that.

RGS

12:41 PM

@Adám I looked for the edit button but maybe I have to create an account and login?

Adám

@RGS You do. This is to avoid spam. We don't have Wikipedia's luxury of thousands of people monitoring 24/7.

RGS

1:26 PM

@Adám Makes sense; did that.

What is the general consensus on edits that one thinks would improve style and/or readability?

Jo King

1:41 PM

@Adám Did you ever get a responses on whether Phase 1 Problem 9 could have negative numbers as input? It doesn't really matter since my code can handle negatives now, but I've run into a similar issue with Phase 2 Problem 8

Adám

@RGS Fine. Like Wikipedia.

RGS

@JoKing that's the balance problem, isn't it?

Adám

@JoKing Yes, it can, and others have found the tests lacking too, but I'm reluctant to make any changes.

Jo King

@RGS yes. My code kinda assumes that all numbers are positive to be a bit more efficient, but I can't think of a way to optimize it if negatives are involved

RGS

@Adám so what I understand is, assuming the edits are made in good faith one can make them.

Adám

1:55 PM

@RGS Absolutely.

Adám

2:54 PM

Announcement: Dyalog Webinar on APL and Microsoft Excel in 5 minutes.

RGS

@Adám 4 :)

xpqz

Is there any Dyalog merchandise? I'd love a Dyalog-branded t-shirt ...

hashtag fanboi

Adám

@xpqz We give branded freebies out to user meetings participants, but I can probably get one of those from past years sent to you.

xpqz

:)

That would be cool!

Adám

@xpqz We have all kinds of things. Carrying bags, backpacks, mugs, cups, battery banks, pens, tote bags, raincoats…

RGS

3:03 PM

@Adám wow, there's plenty of different things

Avi F. S.

3:28 PM

Apologize if anyone has already asked; haven’t seen it. But is the last question of Part II on IBM mobiles guaranteed to have valid input? That is, if row n has three danglies, will n+1 be guaranteed to have three with all of them in the right spots; the rightmost corresponding to the rightmost, leftmost to leftmost, middle to middle? Also, are there guaranteed to only be two danglies on each?

Brian Becker

@AviF.S. Yes, you may assume that 1) the input file is valid and 2) each "line" will consist only of a balance point and left and right end points. Thank you for your participation and question!

xpqz

Can the following be done with an '@'? Given a matrix with two columns (each a vector), and two vectors: values, and rows, can I append the values from the values vector to the first column, in the rows given by the row vector?

Start:

(1 1) (0 0)
(2 1) (0 0)
(3 1) (0 0)
(4 1) (0 0)

values←1 2 3 4
rows← 2 3 4 1

Result:

(1 1 4) (0 0)
(2 1 1) (0 0)
(3 1 2) (0 0)
(4 1 3) (0 0)

RGS

3:49 PM

values@((,∘1)¨rows)⊢mat replaces the first column with the values :P

Now we just have to do something somewhere so that we append the values instead of replacing them

xpqz

Yes. I was stuck at the 'do something somewhere' bit.

dzaima

i've seen similar questions a lot here, and it really seems a new primitive for inserting would be very useful. Question is, what would be a good "insert" primitive?

xpqz

4:04 PM

I think that was possibly the question that preceded adding sql to kdb+/q...

dzaima

@xpqz though in this case, (,¨∘vs)@(rs,¨1)⊢a would do

xpqz

I don't fully understand all the things @ can do yet, by far.

@dzaima See, it's not at all clear to me how that works...

Adám

@xpqz My version: values,¨⍨@1⍤0 1@rows⊢mat

@xpqz It appends 1 to the rows to get full indices for the first column elements.

dzaima

@xpqz rs,¨1 generates the positions of the vectors to be extended, and the left arg gets the items at those positions as an input (e.g. try {⎕←⍵}@(rs,¨1)⊢a), and (,¨∘vs) does a regular transformation on those (equivalent to {⍵,¨vs}), and @ inserts them back

(seems i need to work on my ⎕VI a bit more..)

xpqz

Thank you. I'll dissect these two new insights.

dzaima

4:22 PM

performance comparison because i can't not

Adám

@dzaima Makes sense. Thank you. I was too focused on "forcing" @ to only address the first column, instead of simply building the right full indices.

Avi F. S.

@BrianBecker Thank you very much! Makes things inconceivably easier :)

Adám

@dzaima How are you finding 18.0?

dzaima

@Adám i also don't like the rs,¨1 as can be seen by me looking at my ⎕VI :)

@Adám kind of disappointed by ⍥ not having an inverse, but it's completely understandable as it'd need calling non-inverses in the process which may lead to unwanted problems

should check back on some of my old reports, if i can find them in the mess of files i have :|

Adám

@dzaima Hm, I'll ask Marshall.

dzaima

4:29 PM

@dzaima (to be clear, i only noticed that because i implemented it myself only 11 days ago :p)

@Adám this still happens

RGS

4:41 PM

(@Adám just to manage expectations, should I expect some kind of fix for the weird things that were happening yesterday to my namespaces or should I just circumvent the problem and keep on coding?)

Wezl

5:04 PM

@RGS Linux is a fix that usually works.

Adám

@RGS Code around for now, as I have not had time to look at it today, and I am on holiday tomorrow.

RGS

@Adám Of course ○/ What holiday is it for you tomorrow?

Adám

Shavuot

Shavuot (listen ), Yiddish Shovues (listen ) in Ashkenazi usage, (Hebrew: שָׁבוּעוֹת, lit. "Weeks"), is known as the Feast of Weeks or Pentecost (Koinē Greek: Πεντηκοστή) in English. It is a Jewish holiday that occurs on the sixth day of the Hebrew month of Sivan (it may fall between May 15 and June 14 on the Gregorian calendar).Shavuot has a double significance, agricultural and spiritual. Agriculturally it marks the all-important wheat harvest in the Land of Israel (Exodus 34:22), and spiritually it commemorates the anniversary of the day when God gave the Torah to the nation of Israel assembled...

RGS

@Adám I see, very well! Enjoy your Shavuot :D

Feeds

7:13 PM

0

Q: What are some good resources for getting started with/learning APL?

I'm trying to get started with APL and any related IDEs, tools, compilers, etc. I may need to install locally. I also looked at the APL repl online, but all the symbols seem to be very tough to type (I don't even know where to get started). I would like to know of any online resources, software ...

apl

dzaima

8:42 PM

ugh, figured out why my keyboard was seemingly breaking more lately - each dyalog version has its own aplkeys.sh and i need to edit each of them..

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