ïṠṡ Vector, the Journal of the British APL Association

## Volumes

British APL Association

Archive articles posted online on request: ask the archivist.

Volume 15, No.4

## Solution to APL Crossword from 15.3 ## Crossword from 15.4 Across
1. `V[I]ṪB[(1+ẄB)-I]` for `I` from 1 to `ẄV`, for origin 1 with `(ẄB)=(ẄV)`
5. A random integer from 0 to 4, with 0 half as likely as the others
11. `ỳ(ẄV)+(ẄB)`
13. The matrix `F` with its first `M5` columns made last
14. The values in `A` rounded to the nearest integer (.5 down not up)
15. Are all the elements of the vector `VN` larger than zero?
16. The difference of 102 and one-fifth `S`
18. `(VỲ25)/V`
20. Flag the 52s in `N`
21. Get outta here!
22. `0` where `S=V`, `1` where `S>V`, `Ÿ1` where `S<V`
24. `2Ġ'(0AṫB)ṪC'~'ABCṪ',0`
25. The index of the first row of the matrix `M` that CONTAINS the vector V
27. The number of rows and columns in `K`
28. The vector `1 2 3 ... L`
29. `(RV-1),(RV-2),...,(RV-(10+VC))`
30. An empty vector with the same datatype as the scalar `S`
32. Random one-element vector from `Ÿ1` to `Ÿ9`
33. Get objects from a stored workspace IF they’re not in the active workspace
35. All but the first `N` elements of the vector `V`
36. The number of dimensions in `A`
37. Deal a card from the deck
39. Famous earless APL programmer, _______ Van Go To
40. Deal five cards from the deck

Down
1. `(V)[IO]`
2. Is the vector `A` nonempty?
3. Subtract 12 from each element of `V`; then reverse their order
4. Stick onto matrix `B` a new column, using the numbers in the vector `VR` divided by 20
6. The index of the first row of the matrix `M` that MATCHES the vector `V`
7. Five random numbers from 1 to 25, with replacement
8. `2ṫ109ṫ(9V),9V if (ẄV)9`
9. The available programs
10. The vector `KC` with negative values replaced by zero and padded to length 500
12. A good name for a function that bombs a lot
17. `M+Y-N` without using `+`
19. For a bit vector `A`, where `LẄA`, reshape bits `I` to length `P`, pad to the length of `A`, and compare A to see where neither is true
21. `((ẄV)=0)/L5`
23. Flag the occurrences of the (start of) substring `S` in the vector `V`
25. The first element of any nonempty array `V`, as a scalar
26. The vector `1 2 3...` up to some random number between 1 and 55
31. Cumulative reduction
34. What the circle `ḟ` function is easy as
37. A random integer scalar from 1 to `T`
38. `Ġ'2*5'`

Reprinted with kind permission from Zark APL Tutor News, a quarterly publication of Zark Incorporated, 23 Ketchbrook Lane, Ellington, CT06029, USA

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