Dyalog Ltd.

07/09/2026

2017-09: Write a function that takes a character vector or scalar and returns a Boolean vector indicating anywhere an element is followed by an element of the same value (see https://apl.quest/2017/9/ to test your solution and view ours).

02/09/2026

Last few days to register for Dyalog '26 with guaranteed accommodation at the venue!

If you are intending to join us for Dyalog '26 (and we do hope that you are!) but have not yet registered, you will need to do so before Friday 4 September for guaranteed accommodation at the venue.

For more information and to register, see https://usermeeting.dyalog.com/.

31/08/2026

2017-08: Write a function that takes a Boolean vector or scalar and “turns off” all the 1s after the first 1 (see https://apl.quest/2017/8/ to test your solution and view ours).

Write a function that takes a Boolean vector or scalar and “turns off” all the 1s after the first 1.

28/08/2026

If you are intending to join us for Dyalog '26 (and we do hope that you are!) but have not yet registered, you will need to do so before Friday 4 September for guaranteed accommodation at the venue.

For more information and to register, see https://usermeeting.dyalog.com/

26/08/2026

We are adding information about the presentations that you attend at Dyalog '26 to the user meeting webpages; more will be added as it becomes available.

Don't forget to register to join us for a week of presentations, workshops, and community building! For more information and to register, see https://usermeeting.dyalog.com/

25/08/2026

Congratulations Steve Allen, Amado Cabrera Estrada, and Rohan Prinja, winners of the 2026.2 round of the APL Challenge (our quarterly event aimed at newcomers to APL)!

See https://www.dyalog.com/apl-challenge.htm for more information.

24/08/2026

2017-07: Write a function that takes a character vector representing a DNA string and returns 4 integers of the number of occurrences for each of the symbols 'A', 'C', 'G', and 'T' respectively (see https://apl.quest/2017/7/ to test your solution and view ours).

Write a function that takes a character vector representing a DNA string and returns 4 integers of the number of occurrences for each of the symbols 'A', 'C', 'G', and 'T' respectively.

21/08/2026

In our latest blog post – https://www.dyalog.com/blog/2026/08/hashing-it-out-lookup-performance-in-dyalog-apl/ – Brian examines the impact of hash tables when performing searches. He explores how various factors influence the automatic creation of hash tables and how your knowledge of your code and data can help you to determine whether overriding the defaults will improve performance

17/08/2026

2017-06: Write a function that takes a character vector as its right argument and k (the substring length) as its left argument and returns a vector of the k-mers of the original string (see https://apl.quest/2017/6/ to test your solution and view ours).

Write a function that takes a character vector as its right argument and k (the substring length) as its left argument and returns a vector of the k-mers of the original string.

10/08/2026

2017-05: Write a function that takes a string representing a nucleotide and returns a `1` if it is a valid DNA string, `0` otherwise (see https://apl.quest/2017/5/ to test your solution and view ours).