Re: [Jprogramming] Boxing sparse arrays?

[Martin Kreuzer]

Being definitely no expert on that, but a forum 
search with keywords "sparse array boxed" returned e.g. this post:
http://www.jsoftware.com/pipermail/programming/2017-October/049443.html
As for Roger Stokes' LJ book, see

Section 1.9 'Side By Side Displays', where he states:

"Side-by-side displays are not a feature of the J 
system, but merely figures, or illustrations, in 
this book. They show expressions in the first 
row, and corresponding values below them in the second row. "
So, I don't think that he managed to box sparse arrays.

-M

At 2017-12-23 13:35, you wrote:

Hi all,
Why can't I box sparse arrays?  I was exploring sparse arrays after it came
up on the mailing list and was surprised to get a nonce error when I tried
to box a sparse error.  Using the example given on the dictionary entry for
$. to demonstrate the issue:

   ] d=: (?. 3 4$2) * ?. 3 4$100
 0 56  0  6
85  0  0 96
 0  0 33  0
   ] s=: $. d
0 1 │ 56
0 3 │  6
1 0 │ 85
1 3 │ 96
2 2 │ 33
   s ; d
|nonce error
|   s    ;d
   <s
|nonce error
|       <s
   <d
┌───────────┐
│ 0 56  0  6│
│85  0  0 96│
│ 0  0 33  0│
└───────────┘

I could not find any mention of this nonce error in the dictionary.  Please
let me know if I have overlooked something obvious.  And I am curious how
Roger Stokes managed to box sparse arrays in his LJ book.

Thanks,
Vijay.
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