Places to start

Learning APL or new to Dyalog? Ask "silly" questions here, without fear...

Places to start

Postby Jason|Dyalog on Wed May 06, 2009 8:52 am

On-line help and all Dyalog manuals are available at:

An interactive Tutorial is available at:

And if you want to try apl, then

will allow you to dip your toes into APL.

Another good place to start is the APL Wiki at
Posts: 22
Joined: Tue Sep 09, 2008 2:42 pm

Re: Places to start

Postby larry316 on Wed Dec 14, 2016 3:07 pm

I was looking at APL Wiki and found the Convex Hull Algorithm. Being a newcomer to
dyalog I am not sure how I can implement the D function. Can you provide some help?
Posts: 16
Joined: Thu Dec 01, 2016 4:28 pm

Re: Places to start

Postby JohnS|Dyalog on Wed Dec 14, 2016 4:49 pm

> ... APL Wiki ... Convex Hull Algorithm ... not sure how I can implement the D function

If I understand you correctly, all you need to do is to copy and paste Gianluigi's D function code from the APL Wiki into an edit window in Dyalog.
      )ed ConvexHull
Paste the code into the edit window, making sure you have only one occurrence of the function name "ConvexHull" in the first line.

Re: Places to start

Postby GDR on Tue Jul 04, 2017 3:25 pm

Dear APLer,

I was lucky enough to be an employee at I.P.Sharp Associates when Ken Iverson joined the company around 1981. He developed a 3-day "Working Introduction to APL" course as well as a 3-day companion course for instructors, both of which I attended when given by Ken Iverson himself, and I went on to present the courses myself many times in London.

I was also lucky enough to work for 10 years for Dyadic Systems and latterly Dyalog Limited until 2003 during which time I absorbed a detailed understanding of Dyalog APL.

I set up a small APL company, Graeme Robertson Limited, in 2004 and produced a short course along the lines of Ken's introduction, "A Practical Introduction to APL 1 & APL 2", which proved quite popular. I also produced a far less popular but no less meaty course on the more advanced later additions introduced in Dyalog APL.

Both these courses are freely available as pdf files on my web site,, where you can also find an independent review by Rebecca Burriesci. The course notes are available in book form from Amazon. I am now (in 2017) closing my company and would like to send my remaining copies of these books (original price £9.99 and £29.99) free, except for the cost of post and packing, to anyone who may be interested to either learn/teach APL from scratch, or discover something of the more advanced features of Dyalog APL from a rationalized perspective. (Email me at for your free copy before they run out.)

For those who are amused to hear the best attempts of an ordinary person to express their inner beliefs about life, the universe and everything, may I suggest that you look at the Philosophy page on my web site where you will find a pdf version of my other (non-APL) book available on Amazon. Again I am happy to send this to anyone free on request for the cost of post and packing. I would only ask that, before concluding that this book is ridiculous, read first the other pdf work which is to be found under the Escher drawing on that page. Only then will you be in a proper position to argue that the last half of the book is utter rubbish. I don't think so, and I should be happy to debate any issues you may have arising from your reading of it.

May you live some happy adventures in body and mind as I did,
Graeme D Robertson
Posts: 5
Joined: Thu Nov 26, 2009 9:34 am
Location: Basingstoke, UK

Return to New to Dyalog?

Who is online

Users browsing this forum: No registered users and 1 guest