I saw a video about Dyalog 11 using rational numbers (1r2+1r3 = 5r6). Why is this not in Dyalog anymore? Just curious

Or was it just expirimental and never made it in a final version

Rationals were a suggested feature by Roger Hui, they are implemented in the interpreter even now - they're just not accessible.

Maybe they will be added in a future release - alongside bignums, I imagine

We only need to decide on a syntactical way to denote them. r infix and x postfix for rationals and big integers respectively seems sensible

dfns.dyalog.com/n_rats.htm

interesting, thanks

Could someone please try Nic's covid plot example from his second SharpPlot cultivation to see if you can get it to work? (chat.stackexchange.com/transcript/message/54807543#54807543)

Not sure if the data format has changed, or there is a bug.

I get an index error (tried ⎕IO).

And from stepping through it, I can't make sense of it.

The data set oviously has grown since then, at least.

@awagga I really don't like that x thing. Not sure I like r for rationals either.

@xpqz Yeah me too - essentially looks like countries_to_plot are not found in countries

In fact, I'm only getting Argentina and Mexico

now watch RIDE cry as I attempt to display the whole csv in a ]view window...

lol

@Adám Do you have any alternative ideas?

@xpqz Looks to me like the format of the data changed since that example is written, and maybe some of the columns are called something different. That is, it'll need to be re-written to process the current data - and any notebooks as a result should probably include a link to the current snapshot of that data somehow

@RikedyP yeah -- I loaded up the dataset in a sqlite3 db for that reason.

@xpqz If you used ⎕SH'curl' instead then you could ]open it in default text browser maybe?

just thinking about what to recommend to people in the future

Neither will work on this size dataset. Tried opening as an actual spreadsheet -- gave up waiting. Loading into sqlite3 -- 0.75s. It truly is an inspriational bit of engineering.

and by "loading into" you mean getting it into a state where you can visibly browse and scroll around the data?

Yeah

damn

I might try to cut the data in sqlite to only the relevant columns.

Less massaging of the dataset required then in Dyalog, so the plotting notebook can focus on just the plotting.

@Adám And how about the other suggestions? Like the ~| (⎕p or pi) function, under, underbar rho? Nice to know what developments are being worked on. I have no opinion on wether they are usefull or not.

@awagga If it is a mode, then a plain number can be big int, much like you currently can't see the difference between binary and decimal floats. APL2 uses R for complex numbers in angle form. Maybe Q

@Richard Current suggestions are X⊇Y, f⍥k, f⍛g plus possibly promote rank and demote rank.

Until now, I've though < and > for the last two, but I'm beginning to think that ∧ and ∨ might be better.

@RikedyP When nic converts dates via date←1+{2 ⎕NQ'.' 'DateToIDN'(⍎¨(⍵≠'-')⊆⍵)}¨date -- is the IDN thing here the Dyalog representation (1⎕DT), or something else?

@xpqz Yes, it is.

Ah, that's a relief

@xpqz Note that date←1+{2 ⎕NQ'.' 'DateToIDN'(⍎¨(⍵≠'-')⊆⍵)}¨date can be written as date←40⎕DT'-'(⍎¨≠⊆⊢)¨date

I have unix epoch in the csv file now, so I think it can be done with 20 1⎕DT date

Sure.

@xpqz How did you find getting APL keyboard set up for macOS? Was it straightforward/smooth? Does it gel well enough with what you'd expect? Are there any specific improvements to the information or process that you'd recommend?

@RikedyP Do you want comments here, or happy to email on the topic.

To be fair, it's a long time ago since I did this, but at the time there was a sense of unnecessary friction: why isn't a keyboard layout and fonts etc installed as part of the package?

My expectation was to be able to write APL from the moment I'd installed the downloaded package from Dyalog.

The process itself was (as far as I recall) reasonably pain free. Download this and this file. Put them there and there. Change the following settings. It just felt (at the time) as all of that could have been automatic.

@awagga is there a way to load any of the functions listed in dfns.dyalog.com/n_contents.htm to play around with them?

yes, do )copy dfns or ⎕CY'dfns'

to copy a specific one you can do 'pmat'⎕CY'dfns' (for example)

Dyalog does use floating points internally, past a certain threshold. And yes, big uses characters for it's representation

An alternative approach could make use of nested arrays, or C# BigIntegers now we have a .NET bridge

@gwa000 If you searched APLcart for help with that, but didn't find what you were looking for, please do let me know which search terms you used, so I can add them.

@Adám i was only looking in dfns.dyalog.com/n_contents.htm for how to get at them. just out of curiosity are these user contributed, Dyalog experimental, etc.?

They are a collection of whatever John Scholes found was interesting. Now that he's dead, it is basically a monument for him.

@Steffan Hi there. Interested in APL?

Lol, idk, I was just seeing what cooks in this room

Apples… I mean APLs.

Sounds about right

Ever make APL pie?

Of course: ○

⎕←○1

@awagga 3.141592654

⋄⎕←' _,..---..,_'⋄⎕←' ,-"` .''. `"-,'⋄⎕←' (( ''.''.'' ))'⋄⎕←' `''-.,_ '''' _,.-''`'⋄⎕←' `\ `"""""` /`'⋄⎕←' `""-----""`'

@Steffan
        _,..---..,_
    ,-"`    .'.    `"-,
   ((      '.'.'      ))
    `'-.,_   ''   _,.-'`
      `\  `"""""`  /`
        `""-----""`

I'm hoping to learn APL sometime, it seems interesting

I'll be happy to give you a quick intro (or even extensive tutoring) or point you at various learning resources.

Announcement: I just listed a dozen job positions at SimCorp that involve APL. Hurry up — some have a deadline for applications!